Service Manual

370B
Programmable Curve Tracer
070-A842-50

Warning
The servicing instructions are for use by qualified
personnel only. To avoid personal injury, do not
perform any servicing unless you are qualified to
do so. Refer to all safety summaries prior to
performing service.

www.tektronix.com
Copyright © Tektronix Japan, Ltd. All rights reserved.
Copyright © Tektronix, Inc. All rights reserved.

Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supercedes
that in all previously published material. Specifications and price change privileges reserved.

Tektronix Japan, Ltd., 5-9-31 Kitashinagawa, Shinagawa-ku, Tokyo 141-0001 Japan

Tektronix, Inc., P.O. Box 500, Beaverton, OR 97077

TEKTRONIX and TEK are registered trademarks of Tektronix, Inc.

 WARRANTY

Tektronix warrants that the products that it manufactures and sells will be free from defects in materials and workmanship
for a period of one (1) year from the date of shipment. If a product proves defective during this warranty period, Tektronix,
at its option, either will repair the defective product without charge for parts and labor, or will provide a replacement in
exchange for the defective product.

In order to obtain service under this warranty, Customer must notify Tektronix of the defect before the expiration of the
warranty period and make suitable arrangements for the performance of service. Customer shall be responsible for
packaging and shipping the defective product to the service center designated by Tektronix, with shipping charges prepaid.
Tektronix shall pay for the return of the product to Customer if the shipment is to a location within the country in which the
Tektronix service center is located. Customer shall be responsible for paying all shipping charges, duties, taxes, and any
other charges for products returned to any other locations.

This warranty shall not apply to any defect, failure or damage caused by improper use or improper or inadequate
maintenance and care. Tektronix shall not be obligated to furnish service under this warranty a) to repair damage resulting
from attempts by personnel other than Tektronix representatives to install, repair or service the product; b) to repair
damage resulting from improper use or connection to incompatible equipment; c) to repair any damage or malfunction
caused by the use of non-Tektronix supplies; or d) to service a product that has been modified or integrated with other
products when the effect of such modification or integration increases the time or difficulty of servicing the product.

THIS WARRANTY IS GIVEN BY TEKTRONIX IN LIEU OF ANY OTHER WARRANTIES, EXPRESS OR

IMPLIED. TEKTRONIX AND ITS VENDORS DISCLAIM ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. TEKTRONIX’ RESPONSIBILITY TO
REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND EXCLUSIVE REMEDY PROVIDED TO
THE CUSTOMER FOR BREACH OF THIS WARRANTY. TEKTRONIX AND ITS VENDORS WILL NOT BE
LIABLE FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES IRRESPECTIVE
OF WHETHER TEKTRONIX OR THE VENDOR HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH
DAMAGES.
Table of Contents

General Safety Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii

Service Safety Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi
Contacting Tektronix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv
Specifications
Product Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Performance Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3
Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4
Mechanical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
Functional Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18
Environmental Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19
GPIB Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-22

Operating Information
Operating Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1
Kelvin Sense . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5
Rackmounting Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Repacking for shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-13

Theory of Operation
Theory of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Block Diagram Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
Circuit Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-6

Maintenance
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1
Corrective Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4

Performance Verification
Performance Verification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-1
Using Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-12
CRT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26
Horizontal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-44
Vertical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-54
Step Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-71
Collector Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-104

370B Service Manual i

Table of Contents

AUX Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-119

Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-122
Key Operation and Floppy Disk Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-129

Instrument Options
Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-1
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2

Electrical Parts List

Replaceable Electrical Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
Parts Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-1
Using the Replaceable Electrical Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2

Diagrams
Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-1
Mechanical Parts List
Mechanical Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1
Parts Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-1
Using the Replaceable Parts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-2

ii 370B Service Manual

 Table of Contents

List of Figures

Figure 2-1: Example of Kelvin sense connection . . . . . . . . . . . . . . . . 2-6

Figure 2-2: Location of the Rackmount Latch Release . . . . . . . . . . . 2-7
Figure 2-3: Rackmount hole spacing . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
Figure 2-4: Rackmounting Length and Clearance . . . . . . . . . . . . . . 2-8
Figure 2-5: Rackmounting Hardware . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Figure 2-6: Mounting Stationary Rackmount Sections . . . . . . . . . . . 2-10
Figure 2-7: Cabinet-to-Rackmount Conversion . . . . . . . . . . . . . . . . . 2-12

Figure 3-1: 370B Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-3

Figure 5-1: Diagnostic test pattern display . . . . . . . . . . . . . . . . . . . . . 5-32

Figure 5-2: Looping compensation display . . . . . . . . . . . . . . . . . . . . . 5-40
Figure 5-3: Checking Collector high current range . . . . . . . . . . . . . . 5-67
Figure 5-4: Examining and Adjusting for Step Generator Offset . . 5-73
Figure 5-5: Adjusting for Current Amplifier Bias . . . . . . . . . . . . . . . 5-75
Figure 5-6: Checking for Maximum OFFSET of 200 mA Range . . . 5-83
Figure 5-7: Checking for Maximum Current Output of 100 mA
and 200 mA range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-96
Figure 5-8: Adjusting for Collector Supply Amplifier Offset . . . . . . 5-105
Figure 5-9: Examining for DC and LEAKAGE operation . . . . . . . . 5-113

Figure 8-1: 370B circuit board locator . . . . . . . . . . . . . . . . . . . . . . . . 8-1

Figure 9-1: Cabinet, Rear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-9

Figure 9-2: Display, Front . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-10
Figure 9-3: Chassis Circuit Boards . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-17
Figure 9-4: Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-18
Figure 9-5: Front Panel: L-O-R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-27
Figure 9-6: LV, L-O-R, Looping Circuit Boards . . . . . . . . . . . . . . . . 9-28
Figure 9-7: FDD, Config. Relay, Sense Circuit Boards . . . . . . . . . . . 9-35
Figure 9-8: Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-36

370B Service Manual iii

Table of Contents

List of Tables

Table 1-1: Collector Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-4

Table 1-2: Step Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-7
Table 1-3: AUX Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
Table 1-4: Non-store Vertical Deflection System . . . . . . . . . . . . . . . . 1-10
Table 1-5: Digital Storage Vertical Acquisition . . . . . . . . . . . . . . . . . 1-12
Table 1-6: Non-store Horizontal Deflection System . . . . . . . . . . . . . 1-13
Table 1-7: Digital Storage Horizontal Acquisition . . . . . . . . . . . . . . 1-14
Table 1-8: CRT and Readout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-15
Table 1-9: Adapter Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
Table 1-10: Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
Table 1-11: Surge Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
Table 1-12: Mechanical Specification . . . . . . . . . . . . . . . . . . . . . . . . . 1-17
Table 1-13: Digital Storage Acquisition Mode . . . . . . . . . . . . . . . . . 1-18
Table 1-14: Text Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18
Table 1-15: Environmental Specification . . . . . . . . . . . . . . . . . . . . . . 1-19
Table 1-16: Certifications and Compliances . . . . . . . . . . . . . . . . . . . 1-20
Table 1-17: Installation category and Pollution degree Descriptions 1-21
Table 1-18: GPIB Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-22

Table 2-1: Line voltage ranges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

Table 2-2: Power Cord Color Conductor Identification . . . . . . . . . . 2-2
Table 2-3: Power cord identification . . . . . . . . . . . . . . . . . . . . . . . . . 2-3

Table 4-1: Power-on System Error Messages . . . . . . . . . . . . . . . . . . 4-24

Table 4-2: Front Panel Control Identification . . . . . . . . . . . . . . . . . . 4-25

Table 5-1: Performance Check and Adjustment Procedure Options 5-2

Table 5-2: Performance Check Summary . . . . . . . . . . . . . . . . . . . . . 5-4
Table 5-3: Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-10
Table 5-4: Voltage Regulation and Ripple . . . . . . . . . . . . . . . . . . . . . 5-13
Table 5-5: Base/Emitter Voltage Accuracy . . . . . . . . . . . . . . . . . . . . . 5-48
Table 5-6: Collector Voltage Accuracy . . . . . . . . . . . . . . . . . . . . . . . . 5-50
Table 5-7: Displayed Horizontal Noise . . . . . . . . . . . . . . . . . . . . . . . . 5-53
Table 5-8: Emitter Current Accuracy . . . . . . . . . . . . . . . . . . . . . . . . 5-61
Table 5-9: Collector Current Accuracy . . . . . . . . . . . . . . . . . . . . . . . 5-63
Table 5-10: Collector High Current Accuracy . . . . . . . . . . . . . . . . . 5-67

iv 370B Service Manual

 Table of Contents

Table 5-11: Displayed Vertical Collector Noise in CONFIGURATION

BASE to COLLECTOR SUPPLY mode . . . . . . . . . . . . . . . . . . . 5-70
Table 5-12: OFFSET Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-79
Table 5-13: OFFSET Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-80
Table 5-14: OFFSET Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-82
Table 5-15: Max Peak Volts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-108
Table 5-16: Max Peak Volts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-109
Table 5-17: Maximum Peak Currents . . . . . . . . . . . . . . . . . . . . . . . . 5-111
Table 5-18: Auxiliary Supply Accuracy . . . . . . . . . . . . . . . . . . . . . . . 5-120

Table 6-1: Standard accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2

Table 6-2: Optional accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-2
Table 6-3: Recommended accessories . . . . . . . . . . . . . . . . . . . . . . . . 6-3

370B Service Manual v

Table of Contents

vi 370B Service Manual

General Safety Summary
Review the following safety precautions to avoid injury and prevent damage to
this product or any products connected to it. To avoid potential hazards, use this
product only as specified.
Only qualified personnel should perform service procedures.

To Avoid Fire or Use Proper Power Cord. Use only the power cord specified for this product and
Personal Injury certified for the country of use.
Use Proper Voltage Setting. Before applying power, ensure that the line selector is
in the proper position for the power source being used.
Connect and Disconnect Properly. Do not connect or disconnect probes or test
leads while they are connected to a voltage source.
Ground the Product. This product is grounded through the grounding conductor
of the power cord. To avoid electric shock, the grounding conductor must be
connected to earth ground. Before making connections to the input or output
terminals of the product, ensure that the product is properly grounded.
Observe All Terminal Ratings. To avoid fire or shock hazard, observe all ratings
and markings on the product. Consult the product manual for further ratings
information before making connections to the product.
The common terminal is at ground potential. Do not connect the common
terminal to elevated voltages.
Do not apply a potential to any terminal, including the common terminal, that
exceeds the maximum rating of that terminal.
Do Not Operate Without Covers. Do not operate this product with covers or panels
removed.
Use Proper Fuse. Use only the fuse type and rating specified for this product.
Avoid Exposed Circuitry. Do not touch exposed connections and components
when power is present.
Do Not Operate With Suspected Failures. If you suspect there is damage to this
product, have it inspected by qualified service personnel.
Do Not Operate in Wet/Damp Conditions.
Do Not Operate in an Explosive Atmosphere.
Keep Product Surfaces Clean and Dry.
Provide Proper Ventilation. Refer to the manual’s installation instructions for
details on installing the product so it has proper ventilation.

370B Service Manual vii

General Safety Summary

Symbols and Terms Terms in this Manual. These terms may appear in this manual:

WARNING. Warning statements identify conditions or practices that could result

in injury or loss of life.

CAUTION. Caution statements identify conditions or practices that could result in

damage to this product or other property.

Terms on the Product. These terms may appear on the product:

DANGER indicates an injury hazard immediately accessible as you read the
marking.
WARNING indicates an injury hazard not immediately accessible as you read the
marking.
CAUTION indicates a hazard to property including the product.
Symbols on the Product. The following symbols may appear on the product:

WARNING ProtectiveGround CAUTION Double

HighVoltage (Earth)Terminal Refer to Manual Insulated

viii 370B Service Manual

Service Safety Summary

Only qualified personnel should perform service procedures. Read this Service
Safety Summary and the General Safety Summary before performing any service
procedures.
Do Not Service Alone. Do not perform internal service or adjustments of this
product unless another person capable of rendering first aid and resuscitation is
present.
Disconnect Power. To avoid electric shock, disconnect the mains power by means
of the power cord or, if provided, the power switch.
Use Care When Servicing With Power On. Dangerous voltages or currents may
exist in this product. Disconnect power, remove battery (if applicable), and
disconnect test leads before removing protective panels, soldering, or replacing
components.
To avoid electric shock, do not touch exposed connections.

370B Service Manual

ix
Service Safety Summary

370B Service Manual

x
Preface

This is the service manual for the 370B Programmable Curve Tracer. The manual
contains information needed to service the 370B to the module level.

Manual Structure
This manual is divided into sections, such as Specifications and Theory of
Operation. Further, some sections are divided into subsections, such as Product
Description and Removal and Installation Procedures.
Sections containing procedures also contain introductions to those procedures.
Be sure to read these introductions because they provide information needed to
do the service correctly and efficiently. The following contains a brief description
of each manual section.
H Specifications contains a description of the 370B Programmable Curve
Tracer and the characteristics that apply to it.
H Operating Information includes general information and operating
instructions.
H Theory of Operation contains circuit descriptions that support service to the
module level.
H Performance Verification contains procedures for confirming that the 370B
Programmable Curve Tracer functions properly and meets warranted limits.
H Adjustment Procedures contains a collection of procedures for adjusting the
370B Programmable Curve Tracer to meet warranted limits.
H Maintenance contains information and procedures for performing preventive
and corrective maintenance of the 370B Programmable Curve Tracer. These
instructions include cleaning, module removal and installation, and fault
isolation to the module.
H Options contains information on servicing factory-installed options.
H Electrical Parts List contains a statement referring you to Mechanical Parts
List, where both electrical and mechanical modules are listed.
H Diagrams contains an block diagram and an interconnection diagram.
H Mechanical Parts List includes a table of all replaceable modules, their
descriptions, and their Tektronix part numbers.

370B Service Manual xi

Preface

Manual Conventions
This manual uses certain conventions that you should become familiar with.
Some sections of the manual contain procedures for you to perform. To keep
those instructions clear and consistent, this manual uses the following conven-
tions:
H Names of front panel controls appear in the same case (initial capitals, all
uppercase, etc.) in the manual as is used on the 370B Programmable Curve
Tracer front panel. Front panel names are all upper-case letters; for example,
REF, SAVE, VIEW etc.
H Instruction steps are numbered unless there is only one step.

Modules Throughout this manual, any replaceable component, assembly, or part of the
370B Programmable Curve Tracer is referred to generically as a module. In
general, a module is an assembly (like a circuit board), rather than a component
(like a resistor or an integrated circuit). Sometimes a single component is a
module; for example, the chassis of the 370B Programmable Curve Tracer is a
module.

Safety Symbols and terms related to safety appear in the Safety Summary near the
beginning of this manual.

Finding Other Information

Other documentation for the 370B includes:
H The 370B Programmable Curve Tracer User Manual contains a tutorial to
quickly describe how to operate the370B Programmable Curve Tracer. It also
includes an in-depth discussion on how to more completely use the 370B
Programmable Curve Tracer features.

xii 370B Service Manual

 Preface

Contacting Tektronix

Phone 1-800-833-9200*

Address Tektronix, Inc.

Department or name (if known)
14200 SW Karl Braun Drive
P.O. Box 500
Beaverton, OR 97077
USA

Web site www.tektronix.com

Sales support 1-800-833-9200, select option 1*

Service support 1-800-833-9200, select option 2*

Technical support Email: techsupport@tektronix.com

1-800-833-9200, select option 3*
1-503-627-2400
6:00 a.m. - 5:00 p.m. Pacific time

* This phone number is toll free in North America. After office hours, please leave a
voice mail message.
Outside North America, contact a Tektronix sales office or distributor; see the
Tektronix web site for a list of offices.

370B Service Manual xiii

Preface

xiv 370B Service Manual

Introduction

This manual contains information needed to properly service the 370B Program-
mable Curve Tracer as well as general information critical to safe and effective
servicing.
To prevent personal injury or damage to the analyzer, consider the following
before attempting service:
H The procedures in this manual should be performed only by a qualified
service person
H Read the General Safety Summary and the Service Safety Summary,
beginning on page vii
H Read Preparation for Use in section 2, Operating Information
When using this manual for servicing, be sure to follow all warnings, cautions,
and notes.

Performance Check Interval

Generally, the performance check described in section 4,
Performance Verification, should be done every 12 months. In addition,
performance check is recommended after module replacement.
If the analyzer does not meet performance criteria, repair is necessary.

Strategy for Servicing

Throughout this manual, the term, module, refers to any field-replaceable
component, assembly, or part of the analyzer.
This manual contains all the information needed for periodic maintenance of the
370B Programmable Curve Tracer (Examples of such information are procedures
for checking performance.)
Further, it contains all information for corrective maintenance down to the
module level. To isolate a failure to a module, use the fault isolation procedures
found in Troubleshooting, part of section 6, Maintenance. To remove and replace
any failed module, follow the instructions in Removal and Installation
Procedures, also part of section 6. After isolating a faulty module, replace it with
a fully-tested module obtained from the factory. Section 9, Mechanical Parts
List, contains part number and ordering information for all replaceable modules.

370B Service Manual xv

Introduction

Tektronix Service Offerings

Tektronix provides service to cover repair under warranty as well as other
services that may provide a cost-effective answer to your service needs.
Whether providing warranty repair service or any of the other services listed
below, Tektronix service technicians are well trained to service the waveform
generator. They have access to the latest information on improvements to the
370B as well as new options.

Warranty Repair Service Tektronix warrants this product for one year from date of purchase. The warranty
appears on the back of the title page in this manual. Tektronix technicians
provide warranty service at most Tektronix service locations. The Tektronix
product catalog lists all worldwide service locations.

Self Service Tektronix supports repair to the module level by providing Module Exchange.

Module Exchange. This service reduces down-time for repair by allowing you to
exchange most modules for re-manufactured ones. Each module comes with a
90-day service warranty.

For More Information. Contact your local Tektronix service center or sales
engineer for more information on any of the repair or adjustment services just
described.

xvi 370B Service Manual

Specifications
Product Overview

The 370B Programmable Curve Tracer is a high-performance, GPIB-program-

mable digital storage curve tracer that provides static and dynamic semiconduc-
tor device testing. This versatile instrument stimulates, measures, and displays
the semiconductor characteristics of a variety of two-, three-, and four-terminal
devices; including bipolar transistors, field effect transistors, silicon-controlled
rectifiers, diodes, thyristors, opto-isolators, wafers, integrated circuits, etc.
A variety of measurements can be performed using either grounded-emitter or
grounded-base configurations.
The side, top, and bottom cabinet panels provide protection to personnel from
operating potentials present within the instrument. In addition, they reduce
radiation of electromagnetic interference from the instrument. The cabinet panels
are held in place by screws and four plastic panel retainers. To remove the
panels, remove the four plastic retainers and three additional securing screws at
the rear of the instrument. Pull each panel back to release the front edge. then lift
the panels away from the instrument. Operate the instrument with the panels in
place to protect the interior from dust, and to maintain cooling airflow.
The collector supply produces AC, rectified AC, or DC voltages ranging from 0
to
2000 volts. This high voltage, combined with a current sensitivity of
100 pA/div, permits extended breakdown measurements of a device under test. A
step generator produces voltage or current steps of either polarity for application
to the base or emitter terminal. The step generator may also be operated in a
pulsed mode to control the power dissipated by the DUT.
In addition to conventional curve tracer performance, the 370B Programmable
Curve Tracer includes the following features:
H Digital storage capability that allows bright and stable display and useful
cursor measurements. The 370B has a mass storage system consists of
non-volatile IC memory and 3.5-inch floppy disk drive. Up to 64 families of
characteristic curves and front-panel setups can be stored in a floppy disk.
Up to 16 families of characteristic curves and front-panel setups can also be
stored in non-volatile IC memory. The stored characteristic curves can be
recalled for additional analysis and comparison.
H Two extended acquisition modes, called Averaging and Envelope. Averaging
reduces display noise in high sensitivity ranges. Envelope mode displays
only the maximum and minimum vertical or horizontal excursion of each
curve, which is useful for detecting long-term variations such as thermal
drift.
H Almost all of the 370B front-panel settings can be controlled by GPIB
commands. (Exceptions are those controls intended only for manual

370B Service Manual

1-1
Product Overview

operation, such as INTENSITY, FOCUS, GRAT ILLUM, etc.) Also, curve

data can be sent to or received from an external controller through the GPIB.
H The printer interface permits sending displayed curve data and digital
on-screen readouts to a printer without an external controller.
H Other features include an auxiliary voltage supply, cursor measurement
readout, and diagnostic routines.

370B Service Manual

1-2
Specifications

This section contains the 370B Programmable Curve Tracer specifications. All
specifications are guaranteed unless labeled “typical”. Typical specifications are
provided for your convenience but are not guaranteed.

Performance Conditions
The performance limits in this specification are valid with these conditions:
H The 370B Programmable Curve Tracer must have been calibrated/adjusted at
an ambient temperature between +20_ C and +30_ C.
H The 370B Programmable Curve Tracer must be in an environment with
temperature, altitude, humidity, and vibration within the operating limits
described in these specifications.
H The 370B Programmable Curve Tracer must have had a warm-up period of
at least 20 minutes.
H The 370B Programmable Curve Tracer must be operating at an ambient
temperature between +10_ C and +40_ C.
Warranted characteristics are described in terms of quantifiable performance
limits which are warranted.

370B Service Manual 1-3

Specifications

Electrical Specifications

Table 1-1: Collector Supply

Characteristic Performance Requirement Operating Information
Polarity
+ LEAKAGE AppliespositiveDC voltageto the collectoror
base terminal.Measuresemittercurrent.
Sensitivityis increased1000 times.
+ DC AppliespositiveDC voltageto the collectoror
base terminal.Measurescollectoror base
current.
+ Appliespositivesweptvoltageto the collector
or base terminal.Measurescollectoror base
current.
AC Appliesline-frequencysinewave to the
collectoror base terminal.Measurescollector
or base current.
- Appliesnegativesweptvoltageto the
collectoror base terminal.Measurescollector
or base current.
- DC AppliesnegativeDC voltageto the collector
or base terminal.Measurescollectoror base
current.
- LEAKAGE AppliesnegativeDC voltageto the collector
or base terminal.Measuresemittercurrent.
Sensitivityis increased1000 times.
DC moderipple Lessthan2 % of outputvoltage VARIABLECOLLECTOR SUPPLY at 30 %
(no load) or higher
Lessthan0.5 % of outputvoltage VARIABLECOLLECTOR SUPPLY at 30 %
or less

1-4 370B Service Manual

 Specifications

Table 1-1: Collector Supply (Cont.)

Characteristic Performance Requirement Operating Information
Max peak volts
Max Peak Voltage 16 V, 80 V, 400 V, 2000 V Selectedby the MAX PEAK VOLTS buttons.
Voltageaccuracy Peak opencircuitvoltageon all rangeswithin At MAX PEAK POWER of 50 W.
+15%, -0%
CurrentAvailable In PULSE modeof STEP GENERATOR,
availablecurrentis twotimesof DC mode.
Peak Volts 16 V 80 V 400 V 2000 V In PULSE modeof STEP GENERATOR,
availablecurrentis
il bl ti ttwotimesof
ti f DC mode.
d
Range 10 A 2A 0.4 A 0.05 A
Max Peak Current 20 A 4A 0.8 A 0.1 A
SeriesResistanceAvailable Selectionof 0.26
, 1.3
, 6.4
, 32
,

800
,
160
,
4 k
,
k
20 k
,
k
100 k
,
k

Min/MaxResistance 16 V 80 V 400 V 2000 V
500 k
, 2.5 M
, 12.5 M

Peak VoltsRange
Minimum 0.26 6.4 160 20 k
seriesresistance(
)
Maximum 800 20 k 500 k 12.5 M,
seriesresistance(
)
ResistanceAccuracy Within5 % or 0.2

Peak powerwattsAvailable Derivedfromnominalpeak open-circuit
collectorvoltageand
ll t lt d nominalseries
i l i
16, 80 and 220 W, 50 W, 10 W, 2 W, 0.4 W, 0.08 W
resistancevalues.
400 V range
P = V * V/(4R) for< 220 W
2000 V range 50 W, 10 W, 2 W, 0.4 W, 0.08 W P = (V-I*R)*I for220 W
Variablecollectorsupply
0 - 100.0 % % of maximumpeak voltagevalueis
displayedin the CRT readoutarea. Provides
uncalibratedvariablecollectorsupply
amplitudecontrolfrom0 to 100 % in 0.1 %
increments.
Safetyinterlocks The protectivecovermustbe in placeover
testterminalsand lidshutbeforevoltagecan
be appliedto the terminals.
When protectivecoveris open,collector
supplyis notoperated.
WarningIndicator Red lightindicatesdangerousvoltageis
appliedto collectoror base terminal.
Limitingindicator Indicatesthatinternalsensingcircuit
automaticprotectionis operating.
Loopingcompensation
Range At least100 pF CancelsstraycapacitancebetweenDUT
terminaland ground.

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Specifications

Table 1-1: Collector Supply (Cont.)

Characteristic Performance Requirement Operating Information
Sweep startVoltageAccuracy Applicableto
FULL WAVE mode.Due to
straycapacitancebetweencollectorand
groundterminals,zero-volt-errormay occur
becauseof chargedoffsetvoltage.
16, 80, 400 V range
2 % of MAX Peak Voltage
2000 V Range
15 % of MAX Peak Voltage
Thermalcutoff (typical)
OperatingTemperature 70_C
2.8_C For CollectorSupplyAmplifierand Series
Resistors.
Currentlimit
OperatingPoint At least2.0 A, 1.2 A and 0.2 A of primary Dependson Verticaland Max Peak Volts
currentof collectortransformer. settings.
Voltagelimit
OperatingPoint 50 %, 25 %, 5 % of Max Peak Volts Dependson Horizontaland Max Peak Volts
settings.
ArcKiller Collectorsupplyis disabledat leastone cycle
whilethe relaysor switchesare operated.
OutputControl CircuitBreakermountedon the frontpanel
enablesand disablesCollectorsupply,Step
Generatorand AUX source.
No tripfor1.5 A of CollectorTransformer
primarycurrent.(100 % ratingof circuit
breaker)
Tripoccursbetween3 secondand 80 second
for2.025 A of CollectorTransformerprimary
current.(135 % ratingof circuitbreaker)
NOTE: The collector supply is limited to a maximum continuous peak current operating time under the following duty cycle and ambient
temperature conditions:
50 W. Maximum continuous operating time at rated current (100 % duty cycle) into a short circuit is 20 minutes at 25_C ambient, or
10 minutes at 40_C ambient.
220W. Maximum continuous operating time at rated current(, 100 % duty cycle) into a short circuit is 3 minutes at 25_C ambient, or
90 seconds at 40_C ambient.
Alternatively, the duty cycle may be limited to 50 % at 25_C ambient or 25% at 40_C ambient. (A normal family of transistor curves will
produce a duty cycle effect to 50 % or less, even if operated continuously.)
Collector Supply over-dissipation temporarily shuts off the power, and prints a message on the screen. Collector Supply over-current
trips the OUTPUTS breaker, prints a message on the screen, and reset the Collector Supply output to 0 %. No damage results when
over-dissipation occurs.

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 Specifications

Table 1-2: Step Generator

Characteristic Performance Requirement Operating Information
Accuracy Currentor VoltageStepsincludingOffset.
Incremental 1.5 %
Absolute Lessthan1.5 % of totaloutput+ 3% x STEP
AMPLITUDE setting+ 1 mV or 1 nA.
Lessthan1.5 % of totaloutput+ 10 % x With.1X STEP MULTI pressed.
STEP AMPLITUDE setting+ 1 mV or 1 nA.
Offsetcontrolrange Variablefrom -10 to + 10 timesSTEP
AMPLITUDE.
Resolution STEP AMPLITUDE settingx 1 %
Step transitiontiming(typical) Within3 % of collectorpeak voltsincluding Polarityis in AC mode.
jitter.
Currentmode
Amplituderange 50 nA to 200 mA in a 1 -2-5 sequenceof 21
steps.
Maximumcurrent 20 x STEP AMPLITUDE setting,except10 x Stepsand aidingoffset
STEP AMPLITUDE whencontrolis set to
200 mA.
Maximumvoltage At least10 V Stepsand aidingoffset. 1
Maximumopposingoffsetcurrent 10 x STEP AMPLITUDE
Maximumopposingvolts Lessthan15 V. When the voltagelimiteris workingin
opposingcurrentsettingcondition,the step
generatoroutputcurrentvalueis not
guaranteed.
Rippleplusnoise Lessthan0.5 % x STEP AMPLITUDE + BW = 20 MHz, withopencircuit.
10 nA.
Maximuminductiveload(typical) 1 H
Outputimpedance(typical) More than1/(0.3 % of STEP AMPLITUDE
currentsettingper volt)

Fall and risetime(typical) Within25 s for1 stepor 100 s for10 1 k
load,100 A/step
steps.
Overshootand undershoot Within10 % of transitionamplitude. 1 k
load,100 A/step
(typical)

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Specifications

Table 1-2: Step Generator (Cont.)

Characteristic Performance Requirement Operating Information
VoltageMode
Amplitudeswitchrange 50 mV to 2 V, in a 1-2-5 sequenceof
6 steps
Maximumvoltage 20 x STEP AMPLITUDE
Maximumcurrent At least500mA at 10V or less,at least
200mA at 15 V, at least10 mA at 40 V. 2
Shortcircuitcurrentlimiting 500 mA, +50%, -20%
Maximumopposingoffsetvolts 10 x STEP AMPLITUDE
Maximumopposingcurrent Lessthan20 mA
Rippleplusnoise Lessthan0.5% x STEP AMPLITUDE BW = 20 MHz, withopencircuit.
+ 10 mV
Maximumcapacitiveload 0.01 F
(typical)
OutputImpedance(typical) 200 m
or less
Fall and risetime(typical) Within50 s for1 stepor 100 s for10 1 k
loadat 2 V/step
steps.1 k
load,2 V/step.
Overshoot(typical) Within10 % of transitionamplitude.1 k
1 k
loadat 2 V/step
load,2 V/step.
Step rates 2 x linefrequency(1 x linefrequencyin AC
collectorsupplymode).Stepsoccurat 0
collectorvoltage.
Pulsedsteps 80 s or 300 s wide,
10 % At mesialline,with1 k
load,1 mA /STEP
Stepsand offsetpolarity Correspondsto CollectorSupplyPolarity
whenSTEP GENERATOR POLARITY
INVERT is disabled.
Oppositeto CollectorSupplyPolaritywhen
STEP GENERATOR POLARITY INVERT is
selectedor CONFIGURATION switchis set
to BASE COMMON.
BASE COMMON configurationdisables
STEP GENERATOR POLARITY INVERT.
Numberof steps Rangesfrom0 to 10.

1-8 370B Service Manual

 Specifications

1 Available max current of Step Generator in 100 mA and 200 mA/step.

8 V, 2 A
Step GeneratorCurrent

2A

0A
0V 8V 10 V
LoadVoltage

2 Step Generator max voltage output, in 2 V/step.

0.01 A, 40 V

40 V
Step GeneratorVoltage

0.2 A, 15 V

0.5 A, 10 V
15 V
10 V

0V
10 mA 0.2 A 0.5 A

LoadCurrent

370B Service Manual 1-9

Specifications

Table 1-3: AUX Supply

Characteristic Performance Requirement Operating Information
Range From -40 to +40 volts,with20 mV step
resolution.
Accuracy Within50 mV + 1.5 % of totaloutput
Outputcurrent At least100 mA at
20 V. At least10 mA at

40 V. 3
Ripplepulsenoise Lessthan50 mVp- p

3 Max voltage output and current of AUX SUPPLY.

0.01 A, 40 V

40 V
AUX SupplyVoltage

0.1 A, 20 V

20 V

0V
10 mA 100 mA

LoadCurrent

Table 1-4: Non-store Vertical Deflection System

Characteristic Performance Requirement Operating Information
Cursor WINDOW
Accuracy(typical) Within0.06 division
Collector/BaseCurrent
Range 1 A/divto 2 A/divin a 1-2-5 sequence.
x10 MAG extendsmaximumsensitivityto
100 nA/div(1 nA resolution).
Accuracy(typical) Within2 % of WINDOW cursorreadout+ 0.1
x VERT/DIV setting.

1-10 370B Service Manual

 Specifications

Table 1-4: Non-store Vertical Deflection System (Cont.)

Characteristic Performance Requirement Operating Information
Maximumdisplayednoiseor Excepttorswitchingnoiseat + and
ripple - mode
Max VoltsRange 16 V 80 V 400 V 2000 V
Noiseor Ripple 1 Ap- p 1 Ap- p 2 Ap- p 5 Ap- p
Emittercurrent
Range 1 nA/divto 2 mA/divin a 1-2-5 sequence. CollectorSupplyPolarityis either+LEAK-
x10 MAG extendsmaximumsensitivityto AGE or -LEAKAGEmode.
100 pA/div.
Accuracy Within2 % of WINDOW cursorreadout+0.1
x VERT/DIV settings+ 1 nA
Maximumdisplayednoiseor Dependingon settingof MAX PEAK VOLTS
ripple
Max VoltsRange 16 V 80 V 400 V 2000 V
Noiseor Ripple 1 nAp- p 1 nAp- p 2 nAp- p 5 nAp- p
Step generatordisplay
Range (typical) 1 step/division
1 step/10divisions Withx10 MAG
10 steps/division WithSTEP MULTI .1 x
Accuracy Within0.3 division
Displayoffset(typical)
Range
10 divisionswith0.1 divresolution.
Accuracy Within1.5 % of offset+ 0.1 x VERT/DIV
setting
Displayx10 MAG (typical)
Accuracy Within1.5 % of windowcursorreadout+ 0.3
x VERT/DIV setting.
DisplayInvert(typical)
Accuracy Within0.1 x VERT/DIV setting

370B Service Manual 1-11

Specifications

Table 1-5: Digital Storage Vertical Acquisition

Characteristic Performance Requirement Operating Information
A/D Converter
Resolution 10 bitsfor10.24 divisions,100 countsper
division
Max data points 1024
Max samplingrate Linefrequencyx 1024
Min samplingrate Linefrequencyx 2
Collector/BaseCurrent
Range 1 A/divto 2 A/divin a 1 -2-5 sequence.
x10 MAG extendsmaximumsensitivityto
100 nA/div(1 nA resolution).
Accuracy Within1.5 % of DOT cursorreadout+ 0.05 x
VERT/DIV setting.
EmitterCurrent
Range 1 nA/divto 2 mA/divin a 1-2-5 sequence. Collectorsupplypolarityis either+LEAKAGE
x10 MAG extendsmax sensitivityto 100 or - LEAKAGE
pA/div(1 pA resolution).
Accuracy Within1.5 % of DOT cursorreadout+ 0.05 x
VERT/DIV setting+ 1 nA.
Step Generatordisplay
Range 1 step/division
1 step/10divisions Withx10 MAG
10 steps/division WithSTEP MULTI .1 x
Accuracy Within0.3 division
Displayoffset
Range
10 divisionsin 0.1 divisionresolution
Accuracy Within1.5% of offset+0.06 x VERT/DIV
setting
Displayx10 MAG
Accuracy Within1.5 % of DOT cursorreadout+0.3 x
VERT/DIV setting
DisplayInvert
Accuracy Within0.04 x VERT/DIV setting

1-12 370B Service Manual

 Specifications

Table 1-6: Non-store Horizontal Deflection System

Characteristic Performance Requirement Operating Information
Cursor WINDOW Cursor
Accuracy(typical) within0.06 division
CollectorVolts
Range 50 mV/divto 500 V/divin a 1 -2-5 sequence.
x10 MAG extendsmaximumsensitivityto
5 mV/div(50 V resolution).
Accuracy(typical) Within2 % of WINDOW cursorreadout+ 0.1
x HORIZ/DIV setting.
Maximumdisplayednoise Lessthan0.02 % of MAX PEAK VOLTS
setting.
Base/EmitterVolts
Range 50 mV/divto 5 V/divin a 1-2-5 sequence.
x 10 MAG extendsmaximumsensitivityto
5 mV/div(50 V resolution).
Accuracy(typical) Within2 % of WINDOR cursorreadout+ 0.1
x HORIZ/DIV setting.
Inputimpedance At least100 M

Maximumdisplayednoise Lessthan10 mVp- p With1 M
resistorconnectedbetweenBase
and Emitterterminals,BASE OPEN
configuration,and 0 Numberof Steps.
Step GeneratorDisplay
Range 1 step/division
1 step/10division Withx10 MAG
10 steps/division WithSTEP MULTI .1 x
Accuracy Within0.3 division
DisplayOffset
Range
10 divisionsin 0.1 divisionsteps.
Accuracy Within1.5 % of offset+ 0.1 x HORIZ/DIV
setting.
Displayx10 MAG
Accuracy Within1.5 % of windowcursorreadout+ 0.3
x HORIZ/DIV setting.
DisplayInvert
Accuracy Within0.1 x HORIZ/DIV setting.

370B Service Manual 1-13

Specifications

Table 1-7: Digital Storage Horizontal Acquisition

Characteristic Performance Requirement Operating Information
A/D Converter
Resolution 10 bitsfor10.24 divisions.100 countsper
division.
Max data points 1024
Max samplingrate Linefrequencyx 1024
Min samplingrate Linefrequencyx 2
CollectorVolts
Range 50 mV/divto 500 V/divin a 1-2-5 sequence.
X10 MAG extendsmaximumsensitivityto
5 mV/div(50 V resolution).
Accuracy Within1.5 % of dotcursorreadout+ 0.05 x
HORIZ/DIV setting.
Base/EmitterVolts
Range 50 mV/divto 5 V/divin a 1-2-5 sequences.
x 10 MAG extendsmaximumsensitivityto
5 mV/div(50 V resolution)
Accuracy Within1.5 % of dotcursorreadout+ 0.05 x
HORIZ/DIV setting.
Step Generatordisplay
Range 1 step/division
1 step/10divisions WithX10 MAG
10 steps/division WithSTEP MULTI .1 x
Accuracy(typical) Within0.3 division
Displayoffset
Range
10 divisionsin 0.1 divisionresolution.
Accuracy Within1.5 % of DOT cursorreadout+ 0.01 x
HORIZ/DIV setting.
Displayx10 MAG
Accuracy Within1.5 % of DOT cursorreadout+ 0.3 x
HORIZ/DIV setting.
DisplayInvert
Accuracy Within0.04 % x HORIZ/DIV setting.

1-14 370B Service Manual

 Specifications

Table 1-8: CRT and Readout

Characteristic Performance Requirement Operating Information
CRT
Type Electrostaticdeflection
Phosphor P31
Accelerationpotential 12 kV typical
Screensize 178mm(7 in) diagonalinternalgraticuleand
on-screenscalefactorreadout.
Totaladdressablepoints 1000 x 1000
(graticulearea)
Geometry 0.5 minordivisionor lessof tiltor bowing;
0.75 minordivisionor lessof keystone.
Resolution At least10 lines/div
Spotsize Within0.95 mm at screencenter;elsewhere
on screen:withintwicecentervalue.
Orthogonality 90_, within0.3_
Trace rotationrange(typical) At least
3_
READOUT Automaticon-screendisplay. Over range
shownby a flashingdisplay.
VERT/DIV 100 pA to 2 A
HORIZ/DIV 5 mV to 500 V.
PER STEP 5 nA to 200 mA, and 5 mV to 2 V.
OFFSET 4-digitvalue.
β or gm/DIV 500 x 10 - 9 to 400 x 106 forβ and
50 x 10 - 9 S to 400 S forgm
CURSOR 4-digitHorizontaland Verticalvalueswithout
x 10 MAG, 5-digitwithMAG.
% of COLLECTOR PEAK VOLTS 0.0 % to 100.0 % in 0.1 % step.
AuxSupply - 40.00 V to + 40.00 V

370B Service Manual 1-15

Specifications

Table 1-9: Adapter Connectors

Characteristic Performance Requirement Operating Information
Collector
CollectorSense
Maximumoutputvoltage
2000 V
Maximumoutputcurrent
20 A
Base
Base Sense
Maximumoutputvoltage
400 V
Maximumoutputcurrent
20 A
Emitter
EmitterSense
Maximumoutputvoltage
40 V
Maximumoutputcurrent
20 A
Step Gen Out connector

Maximumoutputvoltage
40 V
Maximumoutputcurrent
2 A
AuxSupplyConnector

Maximumoutputvoltage
40 V @
10 mA, or

and current
20 V @
100 mA.
Ext Base or EmitterConnector

Maximuminputvoltage
40 V
Maximuminputcurrent
2 A

1-16 370B Service Manual

 Specifications

Table 1-10: Power Supply

Characteristic Performance Requirement Operating Information
RatingVoltage 115 VAC / 230 VAC
Linevoltagerange
115 VAC High107 VAC to 132 VAC
Low90 VAC to 110 VAC
230 VAC High214 VAC to 250 VAC
Low180 VAC to 220 VAC
FrequencyRange 48.0 to 63.0 Hz
PowerConsumption Max. 400 W, 3.5 A
Typical120 W, 1.3 A at 115 V, 50 Hz
Fuse
115 VAC 125 V, 4 A, Slow-Blow
230 VAC 250 V, 2 A, Slow-Blow

Table 1-11: Surge Current

Characteristic Description
SurgeCurrent 80 A peak (25_C) for 5 linecycles,afterproducthas been turnedoff forat least30 s.

Mechanical Specifications

Table 1-12: Mechanical Specification

Characteristic Performance Requirement Operating Information
Net Weight
Standardinstrument Approx.37 kg (82 lb)
Option1R Approx.38 kg (84 lb)
Dimensions
Height 326 mm (12.8 in) withfeet
310 mm (12.2 in) withoutfeet
Width 429 mm (16.9 in)
Depth 635 mm (25.0 in)

370B Service Manual 1-17

Specifications

Functional Specifications

Table 1-13: Digital Storage Acquisition Mode

Characteristic Performance Requirement Operating Information
Normal Acquiresand displayedeach curve.
Envelope
VerticalEnvelope Acquiresand displaysthe maximumand
minimumverticalexcursionof each curve.
HorizontalEnvelope Acquiresand displaysthe maximumand
minimumhorizontalexcursionof each curve.
Averaging Acquiresand displaysthe averageof last16
acquisitions.

Table 1-14: Text Display

Characteristic Performance Requirement Operating Information
Alphanumericcharacter ASCII characterset exceptdoublequote(”),
Set (1) u is recognizedas )

GPIB-accessiblewiththe TEXT command.

Alphanumericcharacter A,B,....,Y,Z,(Space),m,u,
Set (2) n,o,,,0,........,9,-,*,(,),

Accessiblewiththe PositionControlbuttons.
Maximumtextstringlength 24 characters
Charactersize Approximately3 mm height,2 mm width.

1-18 370B Service Manual

 Specifications

Environmental Specifications

Table 1-15: Environmental Specification

Characteristic Performance Requirement
Temperature
Operating +10_C to +40_C
Nom-Operating -20_C to +60_C
Transportation -40_C to +65_C
Temperaturegradient
Operating ≤15_C per hour(no condensation)
Non-operating ≤30_C per hour(no condensation)
Humidity
Operatingand Non-operating Five cycles(120 hours)withequipmenttestedat 80 % relativehumidity.Testedon-operating
at 60 _C and operatingto meet MIL-STD-810C method507.1 procedureIV, modifiedas
specifiedin MIL-T-28800B paragraph4.5.1.1.2.
RelativeHumidity
Operating 20 % to 80 % (no condensation)
Maximumwet bulbtemperatureshallbe 29_C.
Storage 10 % to 90 % (no condensation)
Maximumwet bulbtemperatureshallbe 40.0_C.
Transportation 5 % to 95 % (no condensation)
Maximumwet bulbtemperatureshallbe 45.0_C.
Altitude
Operating Up to 3.0 km (10000 feet).
Maximumoperatingtemperaturedecreases1_C each 1,000 feet above1.5 km (5,000 feet).
Non-Operating Up to 15 km (50000 feet).
Vibration
Operating 2.352 m/s2 (0.24 Grms), 5 Hz to 500 Hz
Shock(non-operating) 196 m/s2 (20 G), half-sine,11 ms duration.
Three shocksper axisin each direction(18 shockstotal)
Benchhandling
Operating Dropfrom10 cm (4 in) tilt,or 45 _ whichever less(Tiltnotto balanceto point.)
Packagedtransportationdrop Meets the limitsof the NationalSafe TransitAssociationtestprocedure1A-B-2; 10 dropsof
61cm(24in).
Packagedtransportationvibration Meets the limitsof the NationalSafe TransitAssociationtestprocedure1A-B-1 ;excursionof
2.5cm(1 in) p-p at 4.63 Hz 10.8ms/s2 (1 .1 G) for60 minutes.

370B Service Manual 1-19

Specifications

Table 1-16: Certifications and Compliances

Category Standards or description
EC Declarationof Conformity- Meets intentof Directive89/336/EEC, amendedby 93/68/EEC;
EMC EN 61326-1: 1997 ProductFamilyStandardforElectricalEquipmentforMeasurement,
Control,and LaboratoryUse-EMC Requirement.
Emissions EN 55011 ClassA Radiatedand ConductedEmissions
EN 61000-3-2 PowerLineHarmonic
EN 61000-3-3 LineVoltageAlterationand Flicker
Immunity EN 61000-4-2 ElectrostaticDischargeImmunity
EN 61000-4-3 RadiatedRF ElectromagneticFieldImmunity
Note:The outputlevelof Step Generatormay varyin thistest.
EN 61000-4-4 ElectricalFast Transient/BurstImmunity
EN 61000-4-5 SurgeImmunity
Note:The outputlevelof collectorsupplymay decreasein thistest.
EN 61000-4-6 ConductedDisturbanceinducedby RF FieldImmunity
EN 61000-4-8 PowerFrequencyElectromagneticFieldImmunity
EN 61000-4-11 VoltageDrop,ShortInterruptionsand VoltageVariationsImmunity
Note:The outputof CollectorSupplyis disabledafterthistest.
Australia/NewZealand ComplieswithEMC provisionof RadioCommunicationsActper the followingstandard:
Declarationof Conformity- EMC Industrial,Scientific,and MedicalEquipment:1992
Safety UL3111-1

CAN/CSA C22.2 NO. 1010.1

Self-Declaration EN 61010-1 withsecondamendment
InstallationCategory Powerinput- InstallationCategoryII (as definedin IEC 61010-1, AnnexJ)
PollutionDegree Pollutiondegree2 (as definedin IEC 61010-1)

1-20 370B Service Manual

 Specifications

Table 1-17: Installation category and Pollution degree Descriptions

Characteristics Description
Installation category Terminalson thisproductmay have differentinstallationcategorydesignations.The
installationcategoriesare:

Category Descriptions
CAT III Distribution-levelmains(usuallypermanentlyconnected).
Equipmentat thislevelis typicallyin a fixedindustrial
location
CAT II Local-levelmains(wallsockets).Equipmentat thislevel
includesappliances,portabletools,and similarproducts.
Equipmentis usuallycord-connected
CAT I Secondary(signallevel)or batteryoperatedcircuitsof
electronicequipment
Pollution degree A measureof the contaminatesthatcouldoccurin the environmentaroundand withina
product.Typicallythe internalenvironmentinsidea productis consideredto be the same
as the external.Productsshouldbe usedonlyin the environmentforwhichtheyare rated.

Category Descriptions
PollutionDegree 1 No pollutionor onlydry, nonconductivepollutionoccurs.
Productsin thiscategoryare generallyencapsulated,
hermeticallysealed,or locatedin cleanrooms.
PollutionDegree 2 Normallyonlydry, nonconductivepollutionoccurs.
Occasionallya temporaryconductivitythatis causedby
condensationmustbe expected.Thislocationis a typical
office/homeenvironment.Temporarycondensationoccurs
onlywhenthe productis outof service.
PollutionDegree 3 Conductivepollution,or dry, nonconductivepollutionthat
becomesconductivedue to condensation.These are
shelteredlocationswhereneithertemperaturenorhumidityis
controlled.The area is protectedfromdirectsunshine,rain,
or directwind.
PollutionDegree 4 Pollutionthatgeneratespersistentconductivitythrough
conductivedust,rain,or snow. Typicaloutdoorlocations.

370B Service Manual 1-21

Specifications

GPIB Interface
The IEEE-488-1978 (GPIB) standard defines the GPIB interface functions and
the allowed subsets of those functions.

Table 1-18: GPIB Interface

Function Implemented As
Sourcehandshake SH1
AcceptorHandshake AH1
Talker T6
Listener L4
Servicerequest SR1
RemoteLocal RL2
Parallelpoll PP0
DeviceClear DC1
Devicetrigger DT0
Controller C0

1-22 370B Service Manual

Operating Information
Operating Information

This section provides the following information:

H Initial inspection procedure
H Installation procedures
H Kelvin Sense
H Rackmounting Information
H Repackaging procedure for shipment

Installation

Initial Inspection This instrument was thoroughly inspected for mechanical and electrical defects
before shipment. It should be free of mars or scratches and meet or exceed all
electrical specifications. To confirm this, inspect the instrument for physical
damage incurred in transit and test the electrical performance by following the
First Time Operation in the 370B Programmable Curve Tracer User Manual.

Power Source Information This instrument operates from a power source having a neutral or near ground
(earth) potential. It is not intended for operation from two phases of a multi-
phase system, nor across legs of a single phase, three wire system. This
instrument can be operated from either a 115 volt or 230 volt nominal supply
source, 48 to 63 Hz. Table 2-1 is a listing of the line voltage ranges, line
frequency range, and power consumption.

Table 2-1: Line voltage ranges

RANGE switch NORMAL switch
115 VAC 230 VAC
HIGH 107 VAC to 132 VAC 214 VAC to 250 VAC
LOW 90 VAC to 110 VAC 180 VAC to 220 VAC
Power consumption
Max. 400 W, 3.5 A at 132 V, 60 Hz
Typical 120 W, 1.3 A at 115 V, 50 Hz

370B Service Manual 2-1

Getting Started

Operating Voltage The LINE VOLTAGE SELECTOR switches (NOMINAL and RANGE, located
Selection and Line Fuse on the rear panel) allow selection of the operating line voltage. To select the
Verification correct operating line voltage:
1. Disconnect the 370B from the AC power source before changing the
operating voltage.
2. Select the nominal AC power source voltage with the NOMINAL switch,
and
3. Select the operating line voltage with the RANGE switch.

CAUTION. To prevent damage to the instrument, always check the settings of the
LINE VOLTAGE SELECTOR switches located on the rear panel of the 370B
before connecting the instrument to the line voltage source.

To verify that the power input fuse is for the nominal AC source voltage
selected, perform the following:
1. Use the small straight slot screwdriver to pry the cap (with the attached fuse
inside) out of the fuse holder.
2. Verify proper fuse value:
Nominal voltage 230 V 2 A medium blow
Nominal voltage 115 V 4 A medium blow
3. Install the proper fuse and reinstall the fuse holder cap.

Power Cord Information A power cord with the appropriate plug configuration is supplied with each
instrument. The color coding of the power cord conductors appears in Table 2-2.
Also, should you require a power cord plug other than that supplied, refer to
Table 2-3, Power Cord Identification.

Table 2-2: Power Cord Color Conductor Identification

Conductor Color Alternate
Ungrounded(Line) Brown Black
Grounded(Neutral) LightBlue White
Grounded(ProtectiveGround) Green / Yellow Green / Yellow

370B Service Manual

2-2
 Getting Started

Table 2-3: Power cord identification

Plug configuration Normal usage Option number

NorthAmerica Standard
125 V

Europe A1
220 V

UnitedKingdom A2
240 V

Australia A3
240 V

Switzerland A5
220 V

China AC
240 V

No powercordsupplied. A9

370B Service Manual 2-3

Getting Started

WARNING. This instrument operates from a single phase power source, and has a
detachable three-wire power cord with a two-pole, three-terminal grounding type
plug. The voltage to ground (earth) from either pole of the power source must
not exceed the maximum rated operating voltage (250 volts rms).
Before making connection to the power source, make sure that the instrument is
set for the power source voltage, and is equipped with a suitable plug (two-pole,
three-terminal, grounding type).
This instrument is safety class 1 equipment (IEC* designation). All accessible
conductive parts are directly connected through the grounding conductor of the
power cord to the grounding contact of the power plug. Therefore, the power
plug must only be inserted in a mating receptacle with a grounding contact. Do
not defeat the grounding connection. Any interruption of the grounding
connection can create an electric shock hazard.
For electric shock protection, connect the instrument to ground before connect-
ing to the instrument input or output terminals.
* International Electrotechnical Commission.

Operating Temperature The 370B can be operated where the ambient air temperature is between +10 _C
and +40 _C. After storage at temperatures outside the operating limits, allow the
chassis temperature to reach the safe operating limits before applying power. The
370B is cooled by air drawn in through the air filter on the rear panel and blown
out through holes in the side panels. For proper instrument cooling, provide
adequate clearance on the rear and sides of the instrument to ensure free air flow
and dissipation of heat away from the instrument.

WARNING. Following use of the 370B at high power settings, the device, fixture,
or protective cover may be hot enough to cause injury. Avoid touching any of
these items until cooled.

370B Service Manual

2-4
 Getting Started

Test adapter and To use the 370B to display and measure the characteristic curves of most
Protective cover devices, a test adapter and the protective cover must be installed. Four test
adapters are provided as standard accessories. Six other test adapters are
available as optional accessories. The test adapter is inserted into the adapter
connectors provided on the front panel. These connectors allow two devices to
be set up at a time.

WARNING. Dangerous voltage may appear at the front panel collector and base
terminals. To avoid injury or equipment damage, do not remove the protective
cover.

CAUTION. Double-wide test adapters are designed to fit in the left set of adapter
connectors. If you try to forcibly install a double-wide test adapter in the right
side,you might damage the connector. The connectors are identified by the
following numbers:
A1006
A1007
A1009
A1010

Kelvin Sense
The 370B provides the adaptor connector equipped with Kelvin sense terminals.
The Kelvin sense is the way to measure voltage with two independent terminals
connecting to each of DUT leads; the Force terminal that supplies power and the
Sense terminal senses the voltage. By using the Kelvin sense mechanism, you
can make a high precision measurement because that the effect of conductance
from the contact between the cables and DUT leads is suppressed to a minimum.
The Sense terminals in the 370B adaptor connector and the A1001 through
A1005 test adaptors are for Kelvin sensing. The measurement can be performed
without Sense terminals, however, if you need high precision measurement, use
the those terminals.

370B Service Manual 2-5

Getting Started

Connections for Kelvin When a DUT does not fit in any of the test adaptors and you prepare a specific
Sensing test adaptor, for example, use cables to connect terminals and DUT leads as
shown in Figure 2-1 for Kelvin sensing.

CAUTION. Confirm that the the DUT leads and the force terminals: C, B and E
are firmly connected. Making improper connections may cause the DUT to be
broken. Before a measurement, also verify that the cables are not down and the
contact between the terminals and cables are made properly. To avoid electric
shock and damage to the instrument, perform measurement only within the
protective cover Do not disable the interlock mechanism and/or do not take the
cables out of the protective cover to perform measurement without or outside the
cover.

Figure 2-1: Example of Kelvin sense connection

370B Service Manual

2-6
 Getting Started

Rackmounting Information

Latching The 370B incorporates a spring-latch design built into the rackmounting ear. To
release, pull the rackmount latch release (see Figure 2-2). To relatch, push the
rackmount latch release until the spring latches engage.
For those applications that require additional rackmounting security, the
rackmounting ears of the 370B are drilled for screw fasteners (see Figure 2-2).

Figure 2-2: Location of the Rackmount Latch Release

Rackmounting The 370B fits most commercial consoles and 19-inch racks with rail holes that
conform to universal spacing. See Figure 2-3 for hole spacing details.

WARNING. The 370B weighs more than 36Kg(80 lb). To avoid personal injury,
use care when lifting the instrument, and where required, seek help in lifting and
positioning the 370B into the rack. Once the 370B is installed in a rack, use care
that when extended , the 370B does not tip the rack forward, causing personal
injury or instrument damage.

370B Service Manual 2-7

Getting Started

Figure 2-3: Rackmount hole spacing

When rackmounting the 370B, take note of the following: Allow one inch clear-
ance above and below, and on the left and right sides of the 370B for air circula-
tion. Allow at least three inches of clearance between the 370B rear panel and the
rack enclosure for adequate cooling air and to provide cable clearance. The depth
of the 370B from behind the rack ears to the rear panel is 480mm (18.9 in).
The rack depth must be at least 559 mm (22 in) (see Figure 2-4) to meet the rear
clearance requirement.

Figure 2-4: Rackmounting Length and Clearance

The 370B is 312 mm (12.25 in) high, a multiple of 45 mm (1.75 in) (the
standard rack spacing). If the 370B is installed in a rack with standard hole
spacing, and positioned some multiple of 45 mm (1.75 in) from the bottom or
top, all holes should line up and no drilling should be required.

370B Service Manual

2-8
 Getting Started

The slide-out tracks mount easily to the rack front and rear vertical mounting
rails if the inside distance between the rails is within 503 mm (19.8 in) to
674 mm (26.5 in). If the tracks are to be installed in a rack having other
dimensions, provide extra support (for example, extensions to the rear mounting
brackets) for the rear ends of the slide-out tracks.
The front rack rails must be at least 17 inches apart. The front lip of the
stationary-track section mounts in front of the rail. (Use bar nuts behind
untapped front rails.) The front lip of the stationary track section must mount in
front of the front rail to allow the 370B spring latch to function properly.
The slide-out tracks consist of two assemblies, one for each side of the instru-
ment. Each assembly consists of three sections (see Figure 2-5). The stationary
section of each track attaches to rack rails as shown in Figure 2-6. The chassis
section mounts on the instrument and is installed at the factory. The intermediate
section fits between the other two sections, allowing the instrument to be fully
extended out of the rack.

Figure 2-5: Rackmounting Hardware

370B Service Manual 2-9

Getting Started

The stationary and intermediate sections for both sides are shipped as a matched
set and should not be separated. The package includes matched sets for both
sides and mounting hardware. To identify the assemblies, note that the automatic
latch and intermediate section latch stop holes are located near the top when the
matched sets are properly mated to the chassis sections.
To mount the instrument in a rack, perform the following:
1. Select the appropriate holes in the rack rail, using Figure 2-3 as a guide.
2. Mount the stationary-track sections to the front rack rails with truss head
screws (and bar nuts, if necessary).
3. Mount the stationary-track sections to the rear rails, using one of the
methods depicted in Figure 2-6. Note that the rear mounting bracket can be
installed to fit either deep or shallow cabinet racks.
4. After mounting the instrument in the slide-out tracks, adjust for proper width
by loosening the front and rear screws and allowing the slides to seek the
proper width. Center the instrument, then tighten the screws.

Figure 2-6: Mounting Stationary Rackmount Sections

370B Service Manual

2-10
 Getting Started

5. Push the instrument into the rack, and check that the automatic spring latch
engages the spring latch catch to hold the instrument in place.
6. Extend the instrument out of the rack by pulling the rackmount latch releases
on the front panel (see Figure 2-2) out to disengage the spring latches. Then,
pull the instrument out.
7. Once the instrument is out of the rack, press the latch release and push the
instrument back into the rack.

Rackmount to Cabinet To convert the 370B rackmount version to a cabinet model, use the following
Conversion procedure (see Figure 2-7):
1. Remove the bracket from each comer of the instrument rear panel.
2. Replace the left and right side panels with cabinet model side panels.
3. Mount a carrying handle assembly on the left and right sides of the top.
4. Fasten a foot at each corner on the bottom of the instrument.

370B Service Manual 2-11

Getting Started

Cabinet to Rackmount To convert the 370B cabinet model to a rackmount version, use the following
Conversion procedure (see Figure 2-7):

Figure 2-7: Cabinet-to-Rackmount Conversion

1. Remove the bracket from each comer on the rear panel.

2. Replace the side panels with rackmount version side panels.
3. Attach brackets at each comer on the rear panel.
4. Remove both carrying handle assemblies:
a. Remove the plastic retainer caps that conceal the screws located at each
end of the handle.
b. Remove the screw, spacer and bar nut, then lift off the carrying handle
assembly.

370B Service Manual

2-12
 Getting Started

Repacking for shipment

If this instrument is to be shipped long distances, we recommend that the
instrument be repackaged the same as when it arrived. The cartons and packag-
ing material in which your instrument was shipped should be saved and used for
this purpose.
If your instrument is to be shipped to a Tektronix Service Center for service or
repair, attach a tag to the instrument showing the following:
Owner of the instrument (with address)
Name of a person at your firm to contact
Instrument type
Instrument serial number
Description of the service required
If the original packaging is unfit for use or not available, package the instrument
as follows:
1. Obtain a corrugated cardboard shipping carton with a 170kg(375lb) test
strength that has inside dimensions at least six inches greater than the
instrument dimensions.
2. Surround the instrument with polyethylene sheeting to protect the finish.
3. Cushion the instrument on all sides by tightly packing dunnage or urethane
foam between the carton and the instrument, allowing three inches on all
sides.
4. Seal the carton with shipping tape or with an industrial stapler.
5. Write the address of the Tektronix Service Center and your return address on
the carton in one or more prominent locations.

370B Service Manual 2-13

Getting Started

370B Service Manual

2-14
Theory of Operation
Theory of Operation

This section describes the operation of the 370B Programmable Curve Tracer
circuits. The section is divided into two parts: Block Diagram Description and
Detailed Circuit Operation.

Block Diagram Description

The following description is an overview of the 370B operation. Figure 3-1 is an
overall block diagram of the 370B. The numbers enclosed in diamonds within
each block in Figure 3-1 indicate the schematic diagrams associated with the
block.
The 370B is a static and dynamic semiconductor tester that displays and allows
measurement of static and dynamic semiconductor characteristics obtained under
simulated operating conditions.
The 370B consists of five major functional sections:
H Collector Supply
H Data Acquisition and Display
H Control and Processing
H Interface
H Power Supply

370B Service Manual 3-1

Theory of Operation

Stimulus Generators The Stimulus Generators simulate operating conditions for the DUT by
producing voltages and currents that are applied to the DUT. They include the
Collector Supply, the Step Generator, the Aux Supply, and the PLL and Clock
Circuits.
The Collector Supply produces sine-wave ac, full-wave rectified sine waves
(positive and negative), and positive and negative DC voltages. The amplitude of
the output can be varied from 0 to 2000 volts. The Collector Supply output is
applied to either the collector or the base (or equivalent) terminal of the device
under test.
The Step Generator Circuit produces ascending or descending steps of current or
voltage at a normal rate of one step for each half-sine wave of the Collector
Supply. The amount of current or voltage per step, total number of steps and
offset voltage and current can be controlled. This Step Generator output may be
applied to either the base or the emitter (or equivalent) terminals of the device
under test.
The Auxiliary Supply produces auxiliary power for the DUT. The output voltage
range is
0 to 40 volts. This output can be applied to any terminal of the DUT.

3-2 370B Service Manual

 Theory of Operation

Figure 3-1: 370B Block Diagram

370B Service Manual 3-3

Theory of Operation

The PLL and Clock Circuit generates a synchronous signal for the Step
Generator and the Sine Wave generator. This Circuit also generates synchronous
signals for the Acquisition Circuits.
This block consists of the following circuits.
AUX GEN Circuit
STEP GEN Circuit
SIN GEN Circuit
PLL and CLOCK Circuit
AUX SUPPLY Circuit
Collector Supply Amp Circuit
Step Amp Circuit
H.V. Module Circuit
L.V. Relay Circuit
Collector Terminal Circuit

Data Acquisition and These circuits sense, acquire, and display the effect of the Collector Supply and
Display Step Generator on the DUT. The block consists mainly of the Sense Circuit, the
Acquisition Circuit, the Digital Display Circuit, and the Display Circuit.
The Sense Circuit senses and amplifies voltages and currents of each terminal of
the DUT. This circuit also compensates for errors produced by IR drops between
the DUT terminals and the supply. The amplifier sensitivity is controllable.
The Acquisition Circuit converts sensed analog data into digital data, that is, the
fetch and A/D convert functions. This acquired data is sent to the CPU Circuit.
The Digital Display Circuit converts digital data into analog display signals. This
digital data includes stored curve and operating information.
The Display circuit selects store or non-store data and displays curves and 370B
operating information.
The Data Acquisition and Display Circuits consist of the following:
Acquisition Circuit
Display Counter Circuit
Display D/A Converter Circuit
Display Offset Circuit
Display Select Circuit
Vertical Sense Circuit
Sense Board Interface Circuit
Horizontal Sense Circuit
CRT Output Circuit
H.V. Power Supply Circuit

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 Theory of Operation

Control and Processing These circuits control the 370B and process acquired data. They include the CPU
Circuit, the Front Panel Circuit, and Floppy Disk Circuit.
The CPU Circuit controls an operations of the 370B, including Collector Supply
and Step Generator Control, Sense Circuit Control. CRT Display Control, Front
Panel Control, Floppy Disk Control, etc. The circuit also processes the acquired
data from the device under test. These operations are controlled by the micropro-
cessor and its operating programs through the Address, Data, and Control Bus
lines.
The Front Panel Circuit interfaces the operator to the 370B. This circuit reads
keys, switches and rotary encoder information to set the 370B to the desired
measurement condition. This also displays these settings to the operator by LED
and numerical displays.
The Floppy Disk Circuit memorizes acquired data from the device under test and
the 370B setting information. The data and information are stored in the 3.5-inch
floppy disk.
The Control and Processing Circuits consist of the following:
CPU Circuit
Front Panel Circuit
Floppy Disk Circuit

Interface These circuits interface the microprocessor data with the printer and the
peripheral equipment. The circuit consists of the GPIB (General Purpose
Interface Bus) interface Circuit and the Printer Control Circuit.

Power Supply These circuits supply low-voltage operating power to the 370B. These voltages
in turn are used to generate the high voltages, such as that used on the CRT.
There are two major circuits, the Power Supply and the Interrupt Signal
Generator.
The Power Supply converts the AC line voltages into DC voltages that supply
power for 370B operation.
The Interrupt Signal Generator generates timer interrupt and power fail interrupt
signals. These signals synchronize the 370B circuits, and provide a harmless
shutdown when power fails.

370B Service Manual 3-5

Theory of Operation

Circuit Operation
This part of the Theory of Operation provides a description of the electrical
operation of the 370B. The number enclosed in a diamond preceding a portion of
text denotes the schematic diagram under discussion.

Interconnection This circuit is located on the A1 Mother Board. The circuit connects inter-board
signals of the 370B. These signals include control signals, drive signals, data
signals, reference signals, sense signals, ground lines, and power supply lines.

MPU The MPU circuitry is located on the A2 CPU board. It consists of a 68000
Microprocessor, Power-Up Reset Circuit Clock Generator, Buffers, Wait Timing
Generator, and Interrupt Control Logic Circuit.

Memory The Memory circuit consists of the ROM, RAM, Battery Backup, address
selector, and buffers.

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 Theory of Operation

Generator <4a> The Generator Circuit is located on the A3 A/D Board.

NOTE. The 370B has two step generator output modes, PULSED OFFSE MODE
and DC OFFSET MODE. The Pulse Offset is the default mode.
It can be changed to DC OFFSET MODE with the jumper J310 on the A3 A/D
Board.

CAUTION. When the device under test (DUT) is Normally-On type transistor,
Pulsed Offset will cause additional heat-up for the DUT. For the Normally-On
type transistor, DC Offset mode should be used.

CAUTION. When the device under test (DUT) is Normally-Off type transistor, DC
Offset will cause additional heat-up for the DUT. For the Normally-Off type
transistor, Pulsed Offset mode should be used.

Pulsed Offset. When the measurement mode is set to Single or Sweep, and the
Step Generator Voltage is set, the base line offset is applied only in the internal
measurement operation interval. Pulsed Offset functions only when Step
Generator is PULSE MODE, (short pulseor long).

The number of steps is in the case of 3.

VOLTAGE
or
CURRENT
PULSED
OFFSET

0
PULSED OFFSET MODE TIME

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Theory of Operation

DC Offset. Base line offset voltage is always applied to the DUT in spite of Step
Generator mode and the Measurement Mode setting.

The number of steps is in the case of 3

VOLTAGE
or
CURRENT
DC OFFSET

0
DC OFFSET MODE TIME

Collector Supply The Collector Supply Generator Circuit, located on the A3 A/D board, consists
Generator <4b> of a Sine Wave Timing Generator, Sine Wave Generator, Collector Level Control
Circuit and High Voltage Sine Wave Attenuator Circuit. These circuits generate a
sine wave synchronized to the line frequency, which is the source of the
Collector signal.

Acquisition <5> The Acquisition Circuit, located on the A3 A/D Board, consists of an S/H
(Sample and Hold) and Select Circuit, A/D Circuit. A/D Timing Circuit,
Acquisition Memory Control Circuit, Acquisition Memory Circuit and Bus
Interface Circuit.
These circuits perform A/D conversion of the HD and VD signals from the A5
Display Control Board, write them into Acquisition memory, and transfer data to
the CPU.

Display Counter Circuit The Display Counter Circuit is located on the A4 Digital Display Board. The
<6> Display Counter Circuit consists of the Bus Buffer, the 4.5 MHz Oscillator,
Display Counter, Address Switch & CPU Control, Display RAM. Bus Trans-
ceiver. Dot Cursor Generator, Character & Latch Controller. These circuits
determine whether the CPU accesses the Display RAM, or whether the Display
Counter reads out the Display RAM contents to control signals for the digital
display.

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 Theory of Operation

Display D/A Converter The Display D/A Converter Circuit is located on A4 Digital Display Board. The
Circuit <7> Display D/A Converter Circuit consists of:
X data & Attribute Prefetch Latch
X-Y Data & Attribute Load Latch
X 10-bit DAC & Y 10-bit DAC
X & Y Low-pass Filter
Font Latch
Character ROM & Shift Register
X & Y Readout Position Latch
Readout Attribute Latch
8-bit Adder
X Readout Step Generator
X Readout DAC and Y Readout DAC
These circuits convert the digitized waveform data, readout data and cursor data
from the Display RAM into an analog signal and generate the z-axis signal.

Display Offset Circuit <8> The Display Offset Circuit is located on the A5 Display Control Board. The
Display Offset Circuit consists of the Control Logic Circuit, Offset D/A
Converter, Polarity Select Circuit, Source Select Circuit Zero & Invert Select
Circuit and Gain Select Circuit. These circuits select the horizontal and vertical
source inputs for the CRT display and provide them with calibrated offset
voltages to execute display functions such as DISPLAY OFFSET, MAG, CRT
CAL, DISPLAY INVERT and COLLECTOR SUPPLY POLARITY.

Display Select <9> The Display Select circuit is located on the A5 Display Control board. The
circuit consists of the Signal Select Logic Circuit, Unblank & Z Select Circuit,
and the Horizontal & Vertical Preamp. This circuit block selects and amplifies
the source inputs that are displayed on the CRT. Selection of the source inputs
are performed by the Signal Select Logic Circuit. The Z signal for the source
inputs is controlled by the Un-blank & Z Select Circuit.

Collector Supply Amplifier This circuit is located on the A6 Collector Supply board and the A19 L.V.
<10> Supply board. The circuit consists of the Collector Supply Amplifier Circuit, the
Voltage Limiter Circuit, the Current Limiter Circuit, the Limit Detector Circuit,
the Power Supply and Control Circuit and the Control Signal Decoder Circuit.
These circuits amplify signals from the Sine Wave Generator (located on the A3
A/D board) and provide driving voltage for collector supply transformer.

Step Amplifier <11> The Step Amplifier circuits are located on the A7 Step Generator board. This
circuit transforms the output of the Step Generator on the A/D Board into current
or voltage steps of various amplitudes to be applied to the device under test The
STEP AMPLITUDE switch determines the amplitude of the steps. The circuit

370B Service Manual 3-9

Theory of Operation

consists of the Control Signal Latches, Relay Drivers, 0.5-1-2 Ranging Circuit,
and Step Amplifier. This circuit also includes the Auxiliary Supply Circuit.

H.V. Module <12> This circuit consists of Transformer, H.V. Module, Relay Control Signal Decoder
Circuit and LOR Relay Circuit and is active when the MAX PEAK VOLTS is
set to 2000. These circuits provide the sine-wave ac, the full-wave rectified sine
wave and the DC voltage that range from 0 volts to 2000 volts peak. These
voltages are applied to the collector of the device under test via the A34 LOR
Relay board.

Collector Supply Low This circuit is located on the A9 L.V. Relay board and the A35 Looping board.
Voltage <13> The circuit consists of Transformer, Full-wave Rectifier Circuit. Smoothing
Circuit, Output Power Limiter Circuit, Looping Compensator Circuit, Relay
Control Signal Decoder Circuit, Relay Circuit and Discharging Circuit. These
circuits provide the sine-wave ac, the full-wave rectified sine wave and the DC
voltages. These voltages are supplied in three ranges, from 0 volts to 16 volts,
from 0 volts to 80 volts and from 0 volts to 400 volts. These voltages are applied
to the collector or base of the device under test via the A34 LOR Relay board,
the A10 Sense board and the A33 Configuration Relay Board.

Vertical Sense <14> This circuit is located on the A10 Sense board, and consists of the Sense Board
Interlock Circuit, the Interface Circuit, and the Vertical Sense Circuit. The
interlock Circuit protects this board from generating arcs, overheating, and
operation when the cover is open. The Sense Board Interface Circuit interfaces
this board with the A2 CPU board. The Vertical Sense Circuit compensates for
looping, senses and amplifies collector, emitter and base current.

Horizontal Sense <15a> This circuit consists of the Collector Voltage Sense Circuit, the Base Voltage
Sense Circuit, Overrun Detector Circuit, the Horizontal Amplifier circuit and the
Timer Circuit. It measures either collector or base voltage of the device under
test and eliminates transient voltage on the Collector or Base Terminal.

Low Key Interface <15b> This circuit is located on the A13 Key Interface board, and consists of the Bus
Buffer Circuit, the Address Decoder Circuit, the Rotary Encoder Circuit, the
Status Port Circuit and Lower Panel Key and Display Circuit. These circuits
interface signals with the A2 CPU board, set up VARIABLE COLLECTOR
SUPPLY settings, transfer the status data to the A2 CPU board, control the lower
panel LED displays, and transfer the key input data from the lower panel keys.

Front Panel Key Interface This circuit is located on the A11 Main Key board, and consists of the Bus
<16> Buffer Circuit, the Address Decoder Circuit, the Variable Control Circuit, and
the Switch Matrix Circuit. These circuits interface signals between the A2 CPU

3-10 370B Service Manual

 Theory of Operation

board and the A12 Sub Key board, set up VERTICAL, HORIZONTAL and
STEP AMPLITUDE settings, and control focus and intensity, etc.

Front Panel LED & Key This circuit is located on the A12 Sub Key board, and consists of the Front Panel
<17> Display Circuit and the Front Panel Key Matrix Circuit. The circuit is controlled
by the A11 Main Key board, displays the Main Key setting information, and
transfers key input data from the key matrix.

Configuration LED <18> This circuit is located on the A15 Configuration LED board, and consists of
LEDs and associated components. LEDs display the CONFIGURATION setting
information. When the microprocessor reads address A8030(HEX), the
CONFIGURATION key status is read into the microprocessor.

CRT Output Amplifier This circuit is located on the A18 CRT Output board, and consists of the
<19> Horizontal Output Amplifier, the Vertical Output Amplifier, and the Z-axis
Amplifier. The Horizontal and Vertical Output Amplifiers convert current signals
from the preamplifier of the A5 Display Control board into deflection plate
driving voltages for the CRT. The Z-axis Amplifier converts the current signal
from the unblanking logic of the A5 Display Control board into the driving
voltage for the Grid Bias and DC Restorer Circuit of the A20 H.V. REC board.
The Horizontal and Vertical Output Amplifiers are similar, so only the Horizon-
tal Output Amplifier is discussed here.

Power Supply <20> This circuit is located on the A19 L.V. Supply board and the A27 Primary board.
This board consists of the Primary Circuit, the Low-voltage Power Supply
Circuit and the Interrupt Generator Circuit. This circuit supplies low voltage
power for the 370B and generates the interrupt signals.

H.V. Power Supply <21> The H.V. Power Supply is located on the A20 H.V. REG board. This circuit
consists of the High-voltage Generator Circuit, the High-voltage Regulator
Circuit, the Grid Bias and DC Restorer Circuit, the Focus Amplifier and DC
Restorer Circuit, the Anode Multiplier Circuit, the Rectifier Filter Circuit and the
CRT Circuit. This circuit provides the various high voltage operating potentials
required by the CRT, and displays the 370B data.

GPIB & Printer Interface This circuit is located on the A22 GPIB Interface board. The circuit consists of
<22> the Bus Buffer Circuit, the Address Decoder Circuit, the GPIB Address Switch,
the GPIB Controller Circuit, the GPIB Bus Driver Circuit, the Printer Controller
Circuit and the Printer Bus Driver Circuit. The function of this circuit is to
transfer the microprocessor data to the printer and to communicates with other
instruments via the bidirectional general purpose interface bus (GPIB). These
functions are under control of the microprocessor and the communication
handling software, which are located on the A2 CPU board.

370B Service Manual 3-11

Theory of Operation

Configuration Relay <23> The Configuration Circuit is located on the A23 Configuration Relayboard. This
circuit consists of two relays. These relays are driven by the CONFIGURATION
control.

LOR Key <24> This circuit is located on the A14 LOR Key board, and consists of LEDs and
associated components. LEDs display the LEFT-RIGHT-STANDBY switch
setting information. When the microprocessor reads address A8030(HEX), the
LEFT-RIGHT-STANDBY key status is read into the microprocessor. The
Warning LED indicates that dangerous voltage may be applied to the collector or
base terminals. The Limiter LED indicates that the automatic protection is
operating.

FDD Interface <25> This circuit is located on the A23 FDD Interface board. The circuit consists of
the Bus Buffer Circuit, the Address Decoder Circuit, the FDD Controller Circuit
and the FDD Bus Driver Circuit. The function of this circuit is to communicate
with the FDD unit.

3-12 370B Service Manual

Maintenance
Maintenance

This section of the manual contains information for performing preventive

maintenance, troubleshooting, and corrective maintenance for the 370B
Programmable Curve Tracer.

Preventive Maintenance
Preventive maintenance, when performed on a regular basis, can prevent
instrument breakdown and may improve the reliability of the instrument. The
severity of the environment to which the instrument is subjected will determine
the frequency of maintenance. A convenient time to perform preventive
maintenance is preceding electrical adjustment of the instrument.

Cabinet Removal

WARNING. Dangerous potentials exist at several points throughout this instru-

ment. When the instrument is operated with the covers removed, do not touch
exposed connections or components. Some transistors have voltages present on
the case. Disconnect power before cleaning the instrument or replacing parts.

The side, top, and bottom cabinet panels provide protection to personnel from
operating potentials present within the instrument. In addition, they reduce
radiation of electromagnetic interference from the instrument. The cabinet panels
are held in place by slotted fasteners. To remove the panels, turn each fastener
counterclockwise a quarter turn with a large screwdriver. Lift the panels away
from the instrument. Operate the instrument with the panels in place to protect
the interior from dust.

Cleaning The 370B should be cleaned as often as operating conditions require. Accumula-
tion of dirt in the instrument can cause overheating and component breakdown.
Dirt on components acts as an insulating blanket and prevents efficient heat
dissipation. It also provides an electrical conduction path that may result in
instrument failure.

CAUTION. Avoid the use of chemical cleaning agents that might damage the
plastics used in this instrument. Use a non-residue type of cleaner, preferably
Isopropyl alcohol or totally denatured ethyl alcohol. Before using any other type
of cleaner, consult your Tektronix Service Center or representative.

370B Service Manual 4-1

Maintenance

Exterior. Loose dust accumulated on the outside of the instrument can be

removed with a soft cloth or small brush. The brush is particularly useful for
dislodging dirt on and around the front-panel controls. Dirt that remains can be
removed with a soft cloth dampened in a mild detergent and water solution.
Abrasive cleaners should not be used.

CRT. Clean the plastic light filter, implosion shield, and the CRT face plate with a
soft, lint-free cloth dampened with denatured alcohol.

Interior. Cleaning the interior of the instrument should only be occasionally

necessary. The best way to clean the interior is to blow off the accumulated dust
with dry, low-velocity air (approximately 5 lbs/sq in). Remove any dirt that
remains with a soft brush or a cloth dampened with a mild detergent and water
solution. A cotton swab is useful for cleaning in narrow spaces, or for cleaning
more delicate circuit components.

CAUTION. Circuit boards and components must be dry before applying power to
prevent damage from electrical arcing.
The high-voltage circuits should receive special attention. Excessive dirt in this
area may cause high-voltage arcing and result in improper instrument operation.

Visual Inspection The 370B should be inspected occasionally for such defects as broken connec-
tions, improperly seated semiconductors, damaged or improperly installed circuit
boards, and heat-damaged parts. The corrective procedure for most visible
defects is obvious; however, particular care must be taken if heat-damaged parts
are found. Overheating usually indicates other trouble in the instrument;
therefore, correcting the cause of overheating is important to prevent recurrence
of the damage.

4-2 370B Service Manual

 Maintenance

Semiconductor Checks Periodic checks of the semiconductors are not recommended. The best check of
semiconductor performance is actual operation in the instrument. More details on
semiconductors are given under Troubleshooting later in this section.

Periodic Electrical To ensure accurate measurements, check the electrical adjustment of this
Adjustment instrument after each 2000 hours of operation, or annually if used infrequently.
In addition, replacement of components may necessitate adjustment of the
affected circuits. Complete adjustment instructions are given in Section XXFour,
Performance Check and Adjustment. This procedure can be helpful in localizing
certain troubles in the instrument, and in some cases, may correct them.

370B Service Manual 4-3

Maintenance

Corrective Maintenance
Corrective maintenance consists of instrument repair. Special techniques required
to replace boards in the 370B Programmable Curve Tracer are given here.

Component Removal and

Replacement
WARNING. To avoid electric-shock hazard, always disconnect the instrument
from the power source before removing or replacing components or sub-assem-
blies.

The exploded-view drawings associated with the Replaceable Mechanical Parts

list (located at the rear of this manual) may be helpful in the removal or
disassembly of individual components or sub-assemblies.

Preparations for Component Removal and Replacement. Before removing or

replacing a component, it may be necessary to open or remove panels, key-
boards, etc. The following is the procedure for these preparations.

Cabinet Panel Removal.

1. The 370B has three cabinet panels, top, right, and left.
2. Remove the four cabinet panel retainers from each corner of the 370B rear
panel.
3. Remove the top cabinet panel by first removing its securing screw at the rear.
Slide the panel back to remove it.
4. Remove the right and left cabinet panels by first removing each securing
screw at the rear. Pull each panel back slightly to release it from the front
casting. Then, move the top of the panel outward. Remove each panel by
either sliding it to the rear or by lifting it from the bottom groove in the main
body.
5. Replace cabinet panels in the reverse order of removal.

4-4 370B Service Manual

 Maintenance

Rear Panel Removal.

1. Remove the four cabinet panel retainers from each corner of the rear panel.
2. Remove the top, left, and right cabinet panels from the main body of the
370B. (See the Cabinet Panel Removal instructions.)
3. Remove any connector(s) attached to the outside of the rear panel at the
IEEE STD 488 PORT, the PRINTER INTERFACE PORT, or the AC
INPUT.
4. Remove the six screws securing the rear panel
5. Pull the rear panel out and carefully lower it away from the main body. Do
not stretch any connector wires inside the panel.

NOTE. When removing connectors from a board, tag each one to prevent
misconnection while reassembling.

6. Remove the following connectors from inside the rear panel:

J270 and J274 from the A27 Primary circuit board P16 and P18 from the
FL100 Filter.

NOTE. Remove the A2 CPU and the A3 A/D circuit boards before the next step.
(See the Plug-in Boards removal instructions.)

J220 from the A1 Mother circuit board Both ground wires from the main
body chassis.
7. Remove the rear panel.

NOTE. Removal of the A22 Interface circuit board, the A27 Primary circuit
board, or the B100 Cooling Fan is described later in this section. To remove one
of these circuit boards or the fan from the rear panel, see the removal instruc-
tions for that component.

8. Replace the rear panel in the reverse order of removal.

370B Service Manual 4-5

Maintenance

Connector Replacement.
1. The 370B uses many types of connectors; some of them are very similar in
appearance. Tag each connector before removing to avoid confusing one
connector with another.
2. Some connectors have latches to prevent erroneous removal during
operation. Release these latches when disconnecting them.
3. Be sure to properly orient each connector when reconnecting it.

CAUTION. Some connectors are symmetrical. These are indexed by a mark that
denotes pin 1.

Drawer Unit Removal.

1. Remove the right and left cabinet panels from the main body.
2. Remove the eight screws (four flat-head and four round-head) from each of
the mounting brackets that secure the drawer unit to the main body. Remove
both the right and left mounting brackets.
3. Pull the drawer unit forward away from the 370B.
4. Replace the drawer unit in the reverse order of removal.

NOTE. Before replacing the left or right mounting bracket, make certain that the
label on one access hole is properly aligned with the internal potentiometers.
(The brackets are interchangeable and could be installed on the wrong side.)

4-6 370B Service Manual

 Maintenance

Cathode-Ray Tube Removal.

NOTE. Before removing the CRT, be certain that removal is necessary by

checking associated circuits.

Remove the Cathode-Ray Tube (CRT) as follows:

WARNING. The CRT may retain a dangerous electrical charge. Before removing
the CRT, the anode must be fully discharged by shorting the CRT anode to the
chassis. Wait approximately ten minutes and again firmly short the anode to the
chassis, then remove the CRT.
Use extreme care when handling a CRT. Breakage of the CRT causes a
high-velocity scattering of glass fragments (implosion). Wear protective clothing
and safety glasses. Avoid striking the CRT on any object that might cause it to
crack or implode. When storing a CRT, place it in a protective carton or face
down in a protected location on a smooth surface with a soft mat under the face
plate.

1. Remove the rear panel and the top cabinet panel.

2. Loosen the two screws located on both sides of the CRT base-pin until the
tension of the springs on these screws is released.
3. Remove the CRT base-pin socket from the rear of the CRT.
4. Disconnect the CRT anode cap from the jack located on the left side of the
CRT. Ground the CRT anode to the chassis to dissipate any stored charge
remaining in the CRT.
5. Remove the CRT bezel cover from the lower side of the CRT bezel by
pulling it off with your finger-nail. Remove the CRT bezel from the front
panel by removing the two screws located on the lower side of the bezel.
6. Remove the CRT filter, CRT spacer, and CRT implosion shield from the
CRT frame.
7. Remove the four screws located on the inner sides of the frame.
8. Remove the CRT frame by removing the four remaining screws located on
the outer sides of the CRT frame. Remove the cushion from the CRT face
plate.
9. Remove the graticule illumination lamp assembly from both sides of the
CRT.
10. Hold one hand on the CRT face plate and gently pull out the CRT while
pushing on the CRT base pins.

370B Service Manual 4-7

Maintenance

Cathode-Ray Tube Replacement.

Replace the Cathode Ray Tube (CRT) as follows:
1. Place four CRT retainers into each guide line located at each corner of the
front panel CRT opening.
2. Insert the CRT into the front panel opening and set it firmly against the CRT
clamp ring located at the rear of the CRT shield.
3. Clean the CRT face plate and place the A28 and A29 lamp boards on the
right and left sides of the CRT, respectively.
4. Replace the CRT cushion. Fasten the CRT frame by fixing four screws
located on the outer sides of the CRT frame.
5. Tighten the four screws located on the inner sides of the CRT frame by
applying 5 kg/cm (4.3 inch-lb) of torque.
6. Tighten the two screws beside the CRT base until the springs on the screws
are fully compressed.
7. Replace the CRT base-pin socket on the CRT base pins.
8. Replace the CRT implosion shield, CRT spacer, and CRT filter.
9. Replace the CRT bezel and bezel cover.
10. Reconnect the CRT anode cap.
11. Replace the rear panel and the top cabinet panel.

NOTE. Replacing the CRT requires re-adjustment of the 370B.

4-8 370B Service Manual

 Maintenance

Boards To determine the location of a circuit board, see Figure 8-1 (page 8-1) in Section
of diagrams.

Chassis-Mounted Boards.
Remove and replace all chassis-mounted circuit boards as follows:
1. Disconnect all pin connectors attached to the board, or that connect the beard
to other parts of the instrument.
2. Remove the securing screws.
3. Remove the chassis-mounted board.
4. Replace chassis-mounted boards in the reverse order of removal. Be sure to
match the index arrow or index mark on the multi-pin connector to the
corresponding arrow on the board.

NOTE. To remove a specific circuit board, other circuit boards, chassis parts, or
panels may require removal. If such is the case, refer to the removal instructions
for that assembly as required.

A1 Mother Circuit Board. Remove and replace the A1 Mother circuit board as
follows:
1. Remove the top, left, and right cabinet panels from the main body.
2. Remove A2, A3, A4, and A5 circuit boards from the main body. (See the
Plug-In Boards removal instructions.)
3. Remove the connectors for J10, J12, J110, J180, J190, J220, J400, J410, and
J412 from the board.
4. Remove the connector for J60 from the A6 Collector Supply Output circuit
board. Remove the connector for J70 from the A7 Step Generator circuit
board. Remove the connector for J192 from the A19 L.V. Supply circuit
board.
5. Remove the A1 Mother circuit board by removing the eight screws from the
board.
6. Replace the A1 Mother circuit board in the reverse order of removal.

370B Service Manual 4-9

Maintenance

A2, A3, A4, A5 Plug-in Boards. Remove and replace the plug-in boards as follows:
1. Remove the top cabinet panel from the main body.
2. Remove the two circuit board retainers.
3. Remove the plug-in board by pulling up on the ejector tab at each end of the
board.
4. Replace the plug-in board by aligning the board with the guide slots
(components on the side away from the CRT) and inserting it, holding the
tabs parallel to the top of the board.
5. Slide the board down through the slots until the edge connectors rest on the
bus slot connectors on the A1 Mother board.
6. Push the module down into the bus slot connectors of the A1 Mother board.
Press firmly on the board, but do not press on components.
7. Replace the two circuit board retainers.

A method to change from PULSED OFFSET MODE to DC OFFSET MODE.

NOTE. The 370B has two step generator output modes,PULSED OFFSET
MODE and DC OFFSET MODE. The Pulse Offset is the default mode.
It can be changed to DC OFFSET MODE with the jumper J310 on the A3 A/D
Board.

CAUTION. When the device under test (DUT) is Normally-On type transistor,
Pulsed Offset will cause additional heat-up for the DUT. For the Normally-On
type transistor, DC Offset mode should be used.

CAUTION. When the device under test (DUT) is Normally-Off type transistor, DC
Offset will cause additional heat-up for the DUT. For the Normally-Off type
transistor, Pulsed Offset mode should be used.

4-10 370B Service Manual

 Maintenance

Pulsed Offset. When the measurement mode is set to Single or Sweep, and the
Step Generator Voltage is set, the base line offset is applied only in the internal
measurement operation interval.

DC Offset. Base line offset voltage is always applied to the DUT in spite of Step
Generator mode and the Measurement Mode setting.
1. The A3 A/D BoardA3 is pulled out.
2. Change J310 on the A3 A/D Board Pin 2-3 from Pin 1-2.
(A ∇ mark is attached to pin 1 of J310. Refer to section of diagram
(page 8-5)).

A6 Collector Supply Output Circuit Board. Remove and replace the A6 Collector
Supply Output circuit board as follows:
1. Remove the top and left cabinet panels from the main body.
2. Remove the electrical shield of the A6 Collector Supply Output circuit board
from the main body by removing the four securing screws.
3. Remove the connectors for J60 and J62 from the board and remove the
connector for J64 from the A19 L.V. Supply circuit board.
4. Remove the four screws that secure the heat sink of the board to the chassis.
5. Remove the A6 Collector Supply Output circuit board by removing the two
screws from the board.
6. Replace the A6 Collector Supply Output circuit board in the reverse order of
removal.

CAUTION. If the transistors with heat sink (Q438, Q440, Q538, Q540) are
replaced, make sure that all four insulation washers on the transistors are
placed in position. Without these insulators, destructive electric short circuits
will occur.

NOTE. At the time of replacement, no silicone grease application is required

because of the high heat conductivity of the insulation washer.

370B Service Manual 4-11

Maintenance

A7 Step Generator Circuit Board. Remove and replace the A7 Step Generator
circuit board as follows:
1. Remove the right cabinet panel from the main body.
2. Remove the connectors for J70, J72, and J74 from the board.
3. Remove the three screws located on the lower side of the board.
4. Remove the three screws fastening the heat sink of the board to the main
body. Support the board as these screws are removed so it does not fall and
become damaged.
5. Remove the A7 Step Generator circuit board.
6. Replace the A7 Step Generator circuit board in the reverse order of removal.

A9 L.V. Relay Circuit Board and A35 Looping Circuit Board. The A35 Looping
circuit board is located on the A9 L.V. Relay circuit board. Remove and replace
the A9 L.V. Relay circuit board and the A35 Looping circuit board as follows:
1. Pull out the drawer unit from the main body of the 370B.
2. Remove the guard box assembly cover from the drawer unit by removing the
four screws.

NOTE. When removing connectors from a board, tag each one to prevent
misconnection while reassembling.

3. Remove the connectors for J80, J82, J89, J90, J91, J92A, J92B, J93, J94,
J95, J97, J98, J99, J150, P160, J400, and J410 from the A9 L.V. Relay
circuit board. Remove the connector for J90 from the A10 Sense circuit
board, which is located to the right of the A9 L.V. Relay circuit board.
4. Remove the six screws from the board, and remove the two screws that
secure the heat sink (and board) to the guard box.
5. Remove the A9 L.V. Relay circuit board by grasping the heat sink and lifting
the board.
6. Remove the A35 Looping circuit board from the A9 L.V. Relay circuit board
by removing solder for J84 and J85 connectors of the A35 Looping circuit
board.

4-12 370B Service Manual

 Maintenance

NOTE. The heat sink of the A9 L.V. Relay circuit board is also used as the current
return of the floating ground. Therefore secure firmly the two screws securing the
heat sink to the guard box when replacing the A9 L.V. Relay circuit board.

7. Replace the A9 L.V. Relay circuit board and A35 Looping circuit board in
the reverse order of removal.

A10 Sense Circuit Board and A13 Key Interface Circuit Board. The A13 Key
Interface circuit board is located on the A10 Sense circuit board. Remove and
replace the A10 Sense circuit board and A13 Key Interface circuit board as
follows:
1. Pull out the drawer unit from the main body of the 370B.
2. Remove the connector for J100 from the A13 Key Interface circuit board.
3. Remove the six screws securing the support bracket for the A24 FDD
assembly and the A23 FDD Interface circuit board to the chassis.
4. Remove the bracket with the A24 FDD assembly and A23 FDD Interface
circuit board attached.
5. Remove the connector for J142 from the A13 Key Interface circuit board.

NOTE. Steps 6 and 7 are instructions for removal of the A13 Key Interface board.
Proceed to step 8, if you don ’t need to remove this board.

6. Remove the two screws from the A13 Key Interface circuit board.

NOTE. The A10 Sense circuit board and A13 Key Interface circuit board are
connected to one another by circuit board mounted connectors J130 and P130.
Be careful not to damage the connector when removing and replacing the board.

7. Pull up the A13 Key Interface circuit board to disconnect the interface
connection between the A10 Sense circuit board and A13 Key Interface
circuit board, releasing the two board retaining latches with a pair of pliers.
8. Remove the connectors for J414, J415, J416, J417, and J418 from the A10
Sense circuit board.
9. Remove the P411 connector with cable assembly by removing the two
screws securing the P411 connector to the drawer unit.

370B Service Manual 4-13

Maintenance

NOTE. When removing connectors from a board, tag each one to prevent
misconnection while reassembling.

10. Remove the connectors for J90, J104, J140, J301 , J302, J330, and J419
from the A10 Sense circuit board, and remove the connector for P160 from
the A9 L.V. Relay circuit board.
11. Remove the screw holding the guard box wire lug (which is located to the
front in the guard box) to the guard box chassis.
12. Remove the two flat-head screws securing the heat sink of the A10 Sense
circuit board to the right side of the drawer unit.
13. Remove the six screws from the A10 Sense circuit board.
14. Remove the A10 Sense circuit board.
15. Replace the A10 Sense circuit board and the A13 Key Interface circuit board
in the reverse order of removal.

NOTE. When troubleshooting the A10 Sense circuit board below the A13 Key
Interface, A13 Key Interface circuit board can be used to stand by connecting
P131 on the A13 Key Interface circuit board with J131 on the A10 Sense circuit
board.

A11 Main Key Circuit Board. Remove and replace the A11I Main Key circuit board
as follows:
1. Remove the CRT bezel from the front panel, (See step 5 of the Cathode-Ray
Tube Removal instructions.)
2. Remove the right cabinet panel from the main body.
3. Remove the two securing screws from the right side of the front panel, and
pull out the front panel.
4. Remove the connector for J110 from the A1 Mother circuit board and
remove the screw holding the ground wire lug. Then remove the front panel.
5. Pull out the eight knobs (three large and five small) from the front panel.
6. Remove the A11 Main Key circuit board by removing the six screws
securing the board.

4-14 370B Service Manual

 Maintenance

NOTE. A11 Main Key circuit board and A12 Sub Key circuit board are connected
to one another by circuit board mounted connectors J100, J120, P100 and P120.
Be careful not to damage the connectors when removing and replacing the
board.

7. Replace the A11 Main Key circuit board in the reverse order of removal.

A12 Sub Key Circuit Board. Remove and replace the A12 Sub Key circuit board as
follows:
1. Remove the A11 Main Key circuit board. (See the NOTE in the last part of
the A11 Main Key Circuit Board removal instructions.)
2. Remove the A12 Sub Key circuit board by removing the six spacer posts
from the board.
3. Replace the A12 Sub Key circuit board in the reverse order of removal.

A14 LOR Key Circuit Board. Remove and replace the A14 LOR Key circuit board
as follows:
1. Pull out the drawer unit from the main body of the 370B.
2. Remove the protective box from the Test Adapters.
3. Remove the four flat-head screws securing the Test Adapter Mounting Plate
assembly to the center front of the drawer unit.
4. Remove the two flat-head screws securing the right front panel assembly to
the right front side of the drawer unit.
5. Remove the right front panel assembly by lifting it out.
6. Remove the connector J140 from the A10 Sense circuit board.
7. Remove the A14 LOR Key circuit board by removing the three nuts securing
the board.
8. Replace the A14 LOR Key circuit board in the reverse order of removal.

A15 Configuration LED Circuit Board.

CAUTION. When replacing or removing the rotary encoder S200, tighten the
mounting nuts to a torque of 8 kg/cm when remounting the encoder. Excessive
tightening torque can cause failures.

370B Service Manual 4-15

Maintenance

Remove and replace the A15 Configuration LED circuit board as follows:
1. 1Pull out the drawer unit from the main body of the 370B.
2. Remove the protective box from the Test Adapters.
3. Remove the four flat-head screws securing the Test Adapter Mounting Plate
assembly to the center front of the drawer unit.
4. Remove the two flat-head screws securing the left front panel assembly to
the left front side of the drawer unit.
5. Remove the left front panel assembly by lifting it out.
6. Remove the connectors for J200 and J210 from the board. Remove the
connector for J150 from the A9 L.V. Relay circuit board.
7. Remove the A15 Configuration LED circuit board by removing the two nuts
securing the board.
8. Replace the A15 Configuration LED circuit board in the reverse order of
removal.

A18 CRT Output Circuit Board. Remove and replace the A18 CRT Output circuit
board as follows:
1. Remove the top cabinet panel from the main body of the 370B.
2. Remove the (plastic) insulator by removing its four securing screws from the
A18 CRT Output circuit board.
3. Remove the connectors for J180, J182, J184, and J186 from the board.
4. Remove the A18 CRT Output circuit board by removing the four spacer
posts from the board.
5. Replace the A18 CRT Output circuit board in the reverse order of removal.

A19 L.V.Supply Circuit Board. Remove and replace the A19 L.V. Supply Circuit
board as follows:
1. Remove the top, left, and right cabinet panels from the main body.
2. Remove the rear panel. (See the Rear Panel Removal instructions.)

NOTE. When removing connectors from a board, tag each one to prevent
misconnection while reassembling.

4-16 370B Service Manual

 Maintenance

3. Remove the connectors for J64, J72, J190, J192, J194, J196, J198, J280, and
J290 from the board.
4. Remove the three screws that secure the heat sink of the A19 L.V. Supply
circuit board to the chassis.
5. Remove the A19 L.V. Supply circuit board by removing its three securing
screws from the rear edge of the board.
6. Replace the A19 L.V. Supply circuit board in the reverse order of removal.

A20 H.V. Regulator Circuit Board. Remove and replace the A20 H.V. Regulator
circuit board as follows:
1. Remove the left cabinet panel from the main body.
2. Remove the shield covering the A20 H.V. Regulator circuit board from the
main body by removing the four securing screws.
3. Remove the retainer, that holds the transistor on the board to the chassis, by
removing its screw.

WARNING. The CRT anode circuit retains up to 2400 Volt of charge. Be sure the
anode cap is completely grounded to the chassis before handling the circuit
board.

4. Remove the CRT anode cap from the jack on the left side of the CRT.
Ground the CRT anode cap to the chassis to dispel any stored charge.
5. Remove the connectors for J182, J194, and J200 from the board.
6. Remove the A20 H.V. Regulator circuit board by removing the four screws
from the corners of the board.
7. Replace the A20 H.V. Regulator circuit board in the reverse order of
removal.

A22 Interface Circuit Board. Remove and replace the A22 Interface circuit board
as follows:
1. Remove the A2 CPU and the A3 A/D circuit boards. (See the A2, A3, A4,
and A5 Plug-in Circuit Board removal instructions.)
2. Remove the connector for J220 from the A1 Mother circuit board.
3. Remove the four screws that secure the IEEE STD 488 PORT connector and
the PRINTER INTERFACE PORT connector to the rear panel.

370B Service Manual 4-17

Maintenance

4. Remove the rear panel. (See the Rear Panel Removal instructions.)
5. Remove the A22 Interface circuit board and its (plastic) insulation cover by
removing the four securing screws from the board.
6. Replace the A22 Interface circuit board in the reverse order of removal.

A23 FDD Interface Circuit Board. Remove and replace the A23 FDD Interface
circuit board as follows:
1. Pull out the drawer unit from the main body of the 370B.
2. Remove the connector for J100 from the A13 Key Interface circuit board.
3. Remove the connector (through the W200 on the A23 FDD Interface circuit
board) from the FDD assembly.
4. Remove the A23 FDD Interface circuit board by removing the four securing
screws from the board.
5. Replace the A23 FDD Interface circuit board in the reverse order of removal.

A27 Primary Circuit Board. Remove and replace the A27 Primary circuit board as
follows:
1. Remove the rear panel. (See the Rear Panel Removal instructions.)
2. Remove the connectors for J270, J272, and J274 from the board.

NOTE. Removal of connector J272 may be difficult with the (plastic) insulation
cover installed over the board. The upper corner of the cover may keep one of
the connector’s latches from releasing. Remove the cover first if this problem
occurs.

3. Remove the (plastic) insulation cover and the A27 Primary circuit board by
removing the four securing screws from the board.
4. Replace the A27 Primary circuit board in the reverse order of removal.

A28, A29 Graticule Illumination Lamp Circuit Board. Remove and replace A28 and
A29 Graticule Illumination Lamp circuit boards as follows:
1. Remove the CRT bezel cover from the lower side of the CRT bezel by
pulling it off with your fingernail. Remove the CRT bezel from the front
panel by removing the two screws located on the lower side of the bezel.
2. Remove the (blue) CRT filter, the CRT spacer, and the CRT implosion shield
from the CRT frame.

4-18 370B Service Manual

 Maintenance

3. Remove the CRT frame by first removing the four round head screws from
the inner sides of the frame. Then remove the four flat-head screws from the
outer sides of the CRT frame.
4. Remove the top cabinet panel.
5. Remove connector(s) J280 and/or J290 from the A19 L.V. Supply circuit
board.
6. Remove the (internal scale illumination) light reflector, the light reflector
retainer, and the retainer spring by pulling them out from alongside the CRT
face plate.
7. Remove the A28 or A29 Graticule Illumination Lamp circuit board by
removing the two screws that secure the board in place.
8. Replace the A28 or A29 Graticule Illumination Lamp circuit board in the
reverse order of removal.

A33 Configuration Relay Circuit Board. Remove and replace the A33 Configura-
tion Relay circuit board as follows:
1. Remove the right front panel assembly. (See step 1 through 5 of the A14
LOR Key circuit board removal instructions.)

NOTE. When removing connectors from a board, tag each one to prevent
misconnection while reassembling.

2. Remove the connectors for J102, J103, and J104 from the board.
3. Remove the connectors for J302, J330, and J419 from the A10 Sense circuit
board.
4. Remove the A33 Configuration Relay circuit board by removing the four
screws from the board.
5. Replace the A33 Configuration Relay circuit board in the reverse order of
removal.

A34 LOR Relay Circuit Board. Remove and replace the A34 LOR Relay circuit
board as follows:
1. Remove the A9 L.V. Relay circuit board. (See the A9 L.V. Relay Circuit
Board removal instructions.)
2. Remove the two screws securing the wires to J91 and J95. Remove the
connector for J301 from the A10 Sense circuit board.

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Maintenance

3. Remove the A31 Relay circuit board by removing the six screws securing
the relays on the board to the guard box chassis.
4. Replace the A34 LOR Relay circuit board in the reverse order of removal.

A24 Floppy Disk Drive Assembly. Remove and replace the A24 FDD assembly as
follows:
1. Pull out the drawer unit from the main body of the 370B.
2. Remove the connector (through the W200 on the A23 FDD Interface circuit
board) from the A24 FDD assembly.
3. Remove the A24 FDD assembly by removing the four securing screws from
the FDD assembly.
4. Replace the A24 FDD assembly in the reverse order of removal.

H.V. Relay Module. Remove and replace the H.V. Relay module as follows:
1. Remove the A9 L.V. Relay circuit board. (See the A9 L.V. Relay Circuit
Board removal instructions.)
2. Remove the four screws securing the wires to J8, J11, J12, and J13 on the
Series Resistor module.
3. Remove the H.V. Relay module by removing the four screws securing the
H.V. Relay module to the guard box chassis.
4. Replace the H.V. Relay module in the reverse order of removal.

NOTE. See the label on the Series Resistor module showing the destination of
each wire and connector.

Series Resistor Module. Remove and replace the Series Resistor module as
follows:
1. Remove the A9 L.V. Relay circuit board. (See the A9 L.V. Relay Circuit
Board removal instructions.)

NOTE. When removing connectors from a board, tag each one to prevent
misconnection while reassembling.

2. Remove the six screws securing the wires to J1, J2, J8, J 11, J12, and J13 on
the Series Resistor module. Remove the two screws securing the wires to J91

4-20 370B Service Manual

 Maintenance

and J95 on the A34 LOR Relay circuit board. Remove the screw securing the
wire to J1 on the Input Relay module.
3. Remove the nut holding the guard box wire lug.
4. Remove the Series Resistor module by removing the four screws securing
the module to the guard box chassis.
5. Replace the Series Resistor module in the reverse order of removal.

NOTE. See the label on the Series Resistor module showing the destination of
each wire and connector.

Input Relay Module. Remove and replace the Input Relay module as follows:
1. Perform parts 1 through 4 of the removal instructions for the A10 Sense
circuit board.
2. Remove the three screws securing the wires to J1, J3, and J4 on the Input
Relay module.
3. Remove the Input Relay module and the shield by removing the four screws.
4. Replace the Input Relay module in the reverse order of removal.

NOTE. See the label on the Input Relay module showing the destination of each
wire and connector.

Cooling Fan. Remove and replace the Cooling Fan (B100) as follows:
1. Remove the rear panel. (See the Rear Panel Removal instructions.)
2. Remove the protective cover and remove the connector for J272 from the
A27 Primary Circuit board.
3. Remove the Cooling Fan together with the fan cover, filter, and fan guard by
removing four screws and nuts.

NOTE. Before reinstalling the cooling fan, be certain that the J272 wires are at
the bottom left corner (as facing the rear). Also check that the air flow arrow
marked on the fan housing is pointing toward the inside of the 370B.

4. Replace the Cooling Fan in the reverse order of removal.

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Maintenance

Line Fuse. The line fuse used in the 370B is located within the filter unit on the
rear panel. Replace the line fuse only with one of proper type and rating.
Remove and replace the line fuse as follows:
1. Remove the AC power cable connector from the line filter housing in the
rear panel.
2. Remove the fuse cover by pulling it out from the line filter. Insert some
flat-edged tool (such as a straight-slot, screw-driver blade tip) into the small
groove in the outer left side of the housing. Use the tool to pull, or pry, the
fuse cover loose.
3. Remove the line fuse from its fuse cover.
4. Replace the line fuse in the reverse order of removal.

Semiconductors. Do not replace semiconductors unless actually defective. If

removed from their sockets during routine maintenance, return them to their
original sockets. Unnecessary replacement of semiconductors may affect the
adjustment of the instrument. When semiconductors are replaced, check the
operation of circuits that may be affected.

WARNING. To avoid electric shock hazard, always disconnect the 370B from the
power source before removing or replacing components.

Replacement semiconductors should be of the original type or a direct replace-

ment. When removing soldered-on transistors, use a solder-removing wick to
remove the solder from the circuit board pads.
An extracting tool should be used to remove the in-line integrated circuits to
prevent damaging the pins. This tool is available from Tektronix. Inc.; order
Tektronix part 003-0619-00.
If an extracting tool is not available, use care to avoid damaging the pins. Pull
slowly and evenly on both ends of the integrated circuit. Try to avoid disengag-
ing one end from the socket before the other.

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 Maintenance

Adjustment After Repair After any electrical component has been replaced, the adjustment of that
particular circuit should be checked, as well as the adjustment of any closely
related circuits.

Diagnostic Routines The 370B has four diagnostic routines: Two Power-on Diagnostic routines, a
User Initiated Diagnostic routine, and GPIB diagnostic routine.

Power On Diagnostic Routines. At power on, the 370B runs the Power On
Diagnostic routine to execute the following tests:
Boot ROM check
System RAM check
Display RAM check
Acquisition RAM check
Push button test
After completion of Power on Diagnostic routines, the 370B displays a
“SELFTEST PASS” message at the error message area of the CRT and sets the
initial settings.
If the 370B is turned on with the FAST/SHIFT key pressed, a more detailed
Power On Diagnostic routine is made, in the following order:
Boot ROM check
System RAM check
Display RAM check
Acquisition RAM check
LED check
Display quality check
Push button test
To exit this diagnostic routine, press the FAST/SHIFT button.
H System ROM Check
After confirming that the boot ROMs are in the correct sockets, the 370B
diagnoses the boot ROMs by checksum.
If a boot ROM fatal error is found, (such as misinsertion) the memory index
display blinks with 0 and 1.
When checksum error is found, the error message is displayed on the error
message area of the CRT. The format of this messages is as follows: ROM
000X
When X is the hexadecimal number whose bit 1 through bit 4 respectively
indicates the error status of boot ROMs.

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Maintenance

H System RAM Check

The 370B checks the system RAM by read/write operation. If a system
RAM fatal error is found (such as bus shorted), the memory index display
blinks with 0 and 2.
When read/write errors are found, the error message is displayed on the error
message area of the CRT. The format of this message is as follows:
RAM XXXXX YYYY
Where XXXXX is a hexadecimal representation of the address of the RAM
in error, and YYYY is a hexadecimal representation of error bits in that
address (for example, error message “RAM 00000 0018” indicates that a
read/write error is detected in bit 4 and bit 5 of the system RAM at address
00000).
In the above cases, the 370B does not advance the diagnostics routine.
H Display RAM Check
The 370B checks the Display RAM by read/write operation.
If a read/write error is found (such as bus shorted), the memory index display
blinks with 0 and 3, and the 370A does not advance the diagnostics routine.
H Acquisition RAM Check
The 370B checks the Acquisition RAM by a read/write operation.
If a read/write error is found (such as bus shorted), the memory index display
blinks with 0 and 4, and the 370B does not advance the diagnostics routine.
Table 4-1 shows the Power-on System Error Messages displayed on the
memory index display.
H Acquisition RAM Check
The 370B checks the Flash ROM by checksum.
When a Flash ROM fatal error is founded(such as bus shorted), the memory
index display alternately blinks 0 and 5, and the 370B does not advance to
the next routine.

Table 4-1: Power-on System Error Messages

Display Description
0/1 (blink) SystemROM error(e.g., misinsertion)
0/2 (blink) SystemRAM error(e.g., busshorted)
0/3 (blink) DisplayRAM Read/Writeerror(e.g., busshorted)

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 Maintenance

Table 4-1: Power-on System Error Messages (Cont.)

Display Description
0/4 (blink) AcquisitionRAM Read/Writeerror(e.g., busshorted)
0/5 (blink) FlashROM error(e.g., busshorted)

H LED Check
The 370B turns on all front-panel LEDs sequentially for visual check.
H Display Quality Check
The 370B displays the Logo mark , and a CRT adjustment pattern on the
CRT for CRT control adjustment. For the implementation of this adjustment
pattern, refer to Section of Performance Verification.
Pressing the FAST/SHIFT button exits this routine.
H Push Button Test
The 370B executes push button test (FAST/SHIFT button is not tested in this
case). If an error is found, the error message is displayed at the bottom of the
CRT. The Error Message is indicated by the following format:
<STRING> KEY ERROR
<STRING> identifies the front panel control as listed in Table 4-2.
The following message appears on the text area of the CRT simultaneously
with the above error message:
PRESS FAST KEY TO GO ON
You can ignore the displayed error and push the FAST/SHIFT button to carry
out the measurement, but the displayed key function will not necessarily
occur correctly.

Table 4-2: Front Panel Control Identification

Control Message
DisplayNON STORE NON STORE
DisplaySTORE STORE
DisplayREF REF
DisplayVIEW VIEW
DisplayENTER ENTER
DisplayINVERT INVERT

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Maintenance

Table 4-2: Front Panel Control Identification (Cont.)

Control Message
MEMORY up MEMORY up
MEMORY down MEMORY down
SetupSAVE SAVE
SetupRECALL RECALL
MAX PEAK VOLTS up PEAK VOLTS up
MAX PEAK VOLTS down PEAK VOLTS down
MAX PEAK POWER WATTS up PEAK WATTS up
MAX PEAK POWER WATTS down PEAK WATTS down
CollectorSupplyPOLARITY up POLARITY up
CollectorSupplyPOLARITY down POLARITY down
HARDCOPY HARDCOPY
GPIB PLOT PLOT
ACQ MODE (STORE MODE) up ACQ MODE up
ACQ MODE (STORE MODE) down ACQ MODE down
MeasurementREPEAT REPEAT
MeasurementSINGLE SINGLE
MeasurementSWEEP SWEEP
MAG MAG
FAST/SHIFT FAST/SHIFT
NUMBER OF STEPS up # OF STEPS up
NUMBER OF STEPS down # OF STEPS down
Step GeneratorVOLTAGE VOLTAGE
Step GeneratorCURRENT CURRENT
Step GeneratorOFFSET OPPOSE OPPOSE
Step GeneratorOFFSET AID AID
Step GeneratorPOLARITY STEP POLARITY
Step GeneratorMULTI STEP MULTI
Step GeneratorPULSE PULSE up
AUX up AUX up
AUX down AUX down
CURSOR Mode up CURSOR up
CURSOR Mode down CURSOR down
PositionCURSOR CURSOR

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 Maintenance

Table 4-2: Front Panel Control Identification (Cont.)

Control Message
PositionDISPLAY DISPLAY
PositionControlup POSITION up
PositionControlleft POSITION left
PositionControldown POSITION down
PositionControlright POSITION right
CONFIGURATION up CONFIGURATION up
CONFIGURATION down CONFIGURATION down
LEFT LEFT
STANDBY STANDBY
RIGHT RIGHT
INTERLOCK COVER ON
COVER OFF
VERTICAL CURRENT/DIV VERTICAL XX (0 - 16)
HORIZONTAL VOLTS/DIV HORIZONTAL XX (0 - 16)
STEP AMPLITUDE STEP AMP XX (0 - 16)
VARIABLECOLLECTOR SUPPLY VARIABLEXX (0 - 25)
OUTPUTS OUTPUT ENABLE
OUTPUT DISABLE
PROTECTIVE COVER COVER ON
COVER OFF

H User Initiated Diagnostic Routine

Pressing both the FAST/SHIFT button and Position DISPLAY button enters
the Users Initiated Diagnostic routine. This routine displays a number or
message that corresponds to the front panel push button or rotary switch
pressed or rotated. Thus, you can diagnose whether the front panel controls
are operating normally. Table 4-2 lists the buttons, switches and associated
messages. To exit this routine, press both the FAST/SHIFT button and the
Position DISPLAY button again.
H GPIB Diagnostic Routine
The GPIB TEST? command initiates the 370B boot ROM and RAM
diagnostic routines. The 370B responds to this command by returning boot
ROM and RAM information to the controller in the following format:
TEST ROM:000X (ROM error code)
RAM:YYYY (RAM error code)

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Maintenance

The TEST query response consists of two hexadecimal numbers that indicate
if a ROM or RAM IC was found to be defective. These numbers must be
translated to the binary equivalent to determine the ROM and RAM
locations. (If an ROMs and RAMs are good, the TEST query response is
ROM:0000, RAM:0000.)

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Performance Verification
Performance Verification

The Performance Check and Adjustment Procedure:

H Checks key electrical specifications
H Provides instructions for determining whether adjustment is necessary
H Provides instructions for making all internal adjustments
H Provides optional functional check instructions

Adjustment Interval. To maintain instrument accuracy, check performance every

2000 hours of operation or annually if used infrequently.

NOTE. The Performance Check and Adjustment Procedure is a multipurpose

procedure. Time can be saved by performing only those steps necessary for your
application. Carefully read Table 5-1 to select the appropriate procedure option
for the task to be performed.

370B Service Manual 5-1

Performance Verification

Table 5-1: Performance Check and Adjustment Procedure Options

Task Procedure Options
PerformanceCheck Performthe Power-UpSequenceat the beginningof the PerformanceCheckand Adjustment
(Checkingkey electricalspecifica- Procedure.
tions)
Performthosestepswithtitlesbeginningwith“Checking”and identifiedwitha n in the bar
abovethe heading(see the ProcedureIndexat the beginningof the procedure).
NOTE: If a “Checking” step also contains the word “Adjusting” in the title and a { in the bar
above the title, ignore those parts of the step with adjustment instructions.
Adjustment Performthe Power-UpSequenceat the beginningof the PerformanceCheckand Adjustment
Procedure.
Performonlythosestepswith“Adjusting”in the titleand a { in the bar abovethe title(see the
ProcedureIndexat the beginningof the procedure).
NOTE: Perform all parts of these adjustment steps; most adjustments are preceded by
instructions for determining whether adjustment is necessary and followed by instructions for
verifying that the adjustment was correctly performed.
PerformanceCheckand Adjustment Performthe Power-UpSequenceat the beginningof the PerformanceCheckand Adjustment
Procedure.
Performall stepsin the procedurewitha { or a n (or both)in the bar abovethe steptitle(see
the ProcedureIndexat the beginningof the procedure).
NOTE: Steps for “Examining” characteristics only (i,e., those with no “Checking” or “Adjusting”
instructions included) are not necessary for checking specifications or making adjustments.
PartialPerformanceCheckor Performthe Power-UpSequenceat the beginningof the PerformanceCheckand Adjustment
Adjustment Procedure.
Performthe desiredsteps(e.g., A1, B3, etc.) usingthe SETUP CONDITIONS at the beginning
of each step.
FunctionalCheckof FrontPanel Performthe FirstTime Operationprocedurein the 370B User Manual.
Controlsand Connectors
CompleteFunctionalCheck Performthe Power-UpSequenceat the beginningof the PerformanceCheckand Adjustment
Procedure.
Performonlythosestepswithtitlesbeginningwith“Checking”or “Examining”.
NOTE: If a “Checking or an Examining step also contains the word “Adjusting” in the title and a
{ in the bar above the title, ignore those parts of the step with adjustment instructions.

Before making adjustments, thoroughly clean and inspect the 370B instrument as
instructed in the Maintenance section of this manual.

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 Performance Verification

Using Procedure
The following aids are used in this procedure:

Performance Check Summary. The Performance Check Summary lists key

characteristics checked in the procedure and the procedure steps in which they
are checked. It also indicates which steps contain adjustments which may affect
the specified performance of characteristics.

Power-Up Sequence. The Power-Up Sequence ensures that operating conditions

are stable and repeatable, and must be performed before any complete or partial
procedure is performed.

Initializing the 370B. The 370B is initialized at the beginning of most the 370B
procedure steps to prevent the carry-over of inappropriate setup conditions from
previous steps. Initialization also allows each step to be performed independently
if only portions of the procedure are performed.

Subsection Headings. The procedure is divided into subsections by major circuit

function. For example: A. Power Supply, B. CRT, etc. Each subsection contains
steps to check or adjust characteristics of that major circuit.

Step Titles and Title Bars. The title of each step begins with “checking adjusting”
or “examining”, or a combination of these words.
H Checking indicates that an electrical specification is checked.
H Adjusting indicates that instructions are given to make one or more internal
adjustments.
H Examining indicates that a functional check of the circuit is performed and
that no electrical specifications are checked.
Each step with instructions for checking and/or adjusting instrument characteris-
tics has a title bar positioned over the step title. The title bar contains a n and/or
a { to quickly identify the purpose of the step.

Specifications. All steps that check specifications list those specifications

immediately after the step title.

Setup Conditions. Each step has setup conditions enclosed in a box, which
include all equipment, connections, and control settings necessary to begin the
step.

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Performance Verification

Parts of Steps. Each step is composed of sequential parts with alphabetic

indexing. The parts are arranged into functional groups so that, for instance, if a
performance check is being performed, adjustment instructions may be skipped.

Performance Check Table 5-2 lists key characteristics checked in this procedure and the steps in
Summary which they are checked. Also listed are steps containing adjustment instructions
which may affect a characteristic’s specified performance. The specifications for
characteristics listed in Table 5-2 are given at the beginning of the procedure
step in which they are checked.

Table 5-2: Performance Check Summary

Characteristic Checked Adjusted
Collector Supply
POLARITY Not Specified;examinedin G5
+ LEAKAGE Not Specified;examinedin G5
+ DC Not Specified;examinedin G5
+ Not Specified;examinedin G5
AC Not Specified;examinedin G5
- Not Specified;examinedin G5
- DC Not Specified;examinedin G5
- LEAKAGE Not Specified;examinedin G5
DC Mode Ripple G3
Max Peak Volts G2 G2
VoltageAccuracy G2
Range G2
Max Peak Current G4
Peak PowerWatts G2, G4 G2
VariableCollector0 to 100.0 % Supply Not Specified;examinedin G5
SafetyInterlocks Not Specified;examinedin G5
WarningIndicator Not Specified;examinedin G5
LimiterIndicator Not Specified;examinedin G6, G7
LoopingCompensation Not Specified;examinedin C7 C7
VoltageLimiter G6
CurrentLimiter G7

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 Performance Verification

Table 5-2: Performance Check Summary (Cont.)

Characteristic Checked Adjusted
STEP GENERATOR
Accuracy(Currentor voltagesteps
includingoffset)
Incremental F6, F7, F8, F1, F2
Absolute F4, F5, F9, F10 F1, F2
OffsetControlRange F4, F5
Resolution F4
CurrentMode
AmplitudeRange F5
Max Current F10
Max OpposingVolts F13
OutputImpedance F3
VoltageMode
Amplitudeswitchrange F4
Max voltage F9
Max opposing F11
PulsedSteps F13
Stepsand OffsetPolarity F14
NumberOf Steps F6, F8
AUX SUPPLY
Range (and resolution) H1
Accuracy H1
RipplePlusNoise H2

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Performance Verification

Table 5-2: Performance Check Summary (Cont.)

Characteristic Checked Adjusted
NON STORAGE VERTICAL DEFLECTION SYSTEM
MaximumDisplayedNoiseor Ripple E7 C7
CalibratorVoltage Not Specified;examinedin C1
DIGITAL STORAGE VERTICAL ACQUISITION
CollectorCurrent
Range E6a, E6b
Accuracy E6a, E6b E1, E2
EmitterCurrent
Range E5
Accuracy E5 E1, E3
DisplayOffset
Accuracy C6 C2, C3, C4
DisplayMAG X10 Accuracy E5
DisplayInvertAccuracy C5
NON STORAGE HORIZONTAL DEFLECTION SYSTEM
CollectorVolts
DisplayedNoise D6
Base/EmitterVolts
InputImpedance D5
DisplayedNoise D6
CalibratorVoltage Not Specified;examinedin C1
DIGITAL STORAGE HORIZONTAL ACQUISITION
CollectorVolts
Range D4
Accuracy D4 D1
Base/EmitterVolts
Range D3
Accuracy D3 D1
DisplayOffset
Range C6
Accuracy C6 C2, C3, C4
DisplayMAG X10 Accuracy D2
DisplayInvertAccuracy C5

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 Performance Verification

Table 5-2: Performance Check Summary (Cont.)

Characteristic Checked Adjusted
CRT
CathodeVoltage Not Specified;examinedin B1
Intensity Not Specified;examinedin B2 B2
Astigmatismand Focus Not Specified;examinedin B3 B3
IntensityControls Not Specified;examinedin B4, B5,
B6
Geometry C4 C4
Orthogonality C4 C4
POWER SUPPLY
Deviation Not Specified;examinedin A1
Ripple Not Specified;examinedin A1
PLL A2
ReferenceVoltage A3 A3

Power-Up Sequence The performance of this instrument can be checked at any ambient temperature
from +10 _C to +40 _C unless otherwise stated. Adjustment must be made at an
ambient temperature from +20 _C to +30 _Cfor the specified tolerances to apply.

WARNING. Adjustment of the 370B should only be performed by a qualified

service technician.

1. Check that the 370B has been set for the proper power source, and that a
suitable power cord has been attached.
2. Remove the 370B cabinet panels to gain access to internal adjustment and
test points.
For instructions on cabinet panel removal, refer to the description under the
heading COMPONENT REMOVAL AND REPLACEMENT in Section 4 of
this manual.

WARNING. Use extreme care when operating the 370B with the covers removed,
due to the line voltage, high voltage, and high current levels present.

3. Connect the 370B to a suitable power source.

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Performance Verification

4. Press the POWER button and allow at least 20 minutes warmup before
proceeding.

Initializing the 370B The following procedure saves the power-up default 370B settings for use when
the procedure calls for you to “Initialize the 370B”.
1. Press the SETUP SAVE button to store the default settings in memory
location 1.
These default settings plus the manual initialization settings are used as
starting settings throughout this procedure, expect as noted otherwise.
2. Now, to Initialize the 370B:
a. Press the SETUP RECALL button (with the MEMORY index set to
location 1).
b. Make the additional manual settings:

OUTPUTS ENABLED
ProtectiveCover Closed

The power-up default settings are as follows:

DISPLAY
Mode STORE
VERTICAL 2 A COLLECTOR
HORIZONTAL 2 V COLLECTOR
INVERT Off
COLLECTOR SUPPLY
MAX PEAK VOLTS 16
MAX PEAK POWER WATTS 0.08
POLARITY +
STEP GENERATOR
Mode CURRENT
STEP AMPLITUDE 50 nA
NUMBER OF STEPS 5
OFFSET 0.0 nA
POLARITY +
INVERT Off
STEP MULTI .1X Off

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 Performance Verification

PULSE Off
ACQ MODE NORM
MEASUREMENT REPEAT
MAG X10 Off
POSITION CURSOR
CURSOR OFF
AUX SUPPLY 0.00 V
CONFIGURATION BASE STEP GEN
VARIABLECOLLECTOR SUPPLY 0%
RIGHT-LEFT-STANDBY STANDBY

Test Equipment The test equipment listed in Table 5-3 is required for a complete Performance
Check and Adjustment of the instrument. However, complete checking or
adjusting may not always be necessary or desirable. You may be satisfied with
checking only selected characteristics, thereby reducing the amount of test
equipment actually required.
The specifications for test equipment listed in Table 5-3 are the minimum
required to check performance requirements of the 370B. Detailed operating
instructions for test equipment are not given in these procedures; refer to the test
equipment instruction manual if more information is needed.

Special Futures Special fixtures are used where they facilitate instrument adjustment. These
fixtures are available from Tektronix, Inc. Order by part number from Tektronix
Field Offices or representatives.

Test Equipment The checks and adjustment procedures are based on the first item of equipment
Alternatives given as an example. When other equipment is substituted, control settings or
setups may have to be altered. If the exact item of equipment given as an
example in Table 5-3 is not available, first check the Minimum Specifications
column carefully to see if any other equipment might suffice. Then check the
Purpose column to see where this item is used. If used for a performance check
or adjustment that is of little or no importance for your measurement require-
ments, the item and corresponding step(s) can be deleted.

370B Service Manual 5-9

Performance Verification

Table 5-3: Test Equipment

Item Minimum Specification Purpose Example of Applicable Test
Equipment
1. Test Oscilloscope Bandwidth,DC to 150 MHz; Used to checkripple. a. Tektronix2445B 150 MHz
deflectionfactor, 2 mV to 5 OscilloscopewithP6137 Probe.
V/div(with10X, 10 M
probe)
b. Refer to TektronixProducts
catalogforcompatibleequip-
ment.
2. Calibrator Voltagerange:500.0 mV to Suppliesa referencevoltageto Fluke5101B
1000 V; Accuracy:0.1 mV; the 370B.
Resolution:0.1 mV, Current
range:10.00 A to 1.999 A;
Accuracy:0.1 %
3. DigitalMultimeter 4.5 digitDCV: 1000 V, Accura- Used throughoutthe checks a. Fluke8505A Option02A, 03
cy:0.05 %; Resolution:0.1 mV; and adjustmentsto measure
Inputimp:10,000 M
(100 mV, voltage,currentand resistance. b. Keithley195A W/OP 1950
1 V, 10 V range):DCA: 1.28 A;
Accuracy:0.1 nA;
: 25 M
;
Accuracy:0.05 %; Resolution;
0.01

4.5 digitDCV: 1000 V, Accura- Used to examine -2400 V TektronixDM501A
cy:0.05 %; Resolution:0.1 mV;
InputImp:10 M
(20 V range)
4. Tool,Alignment Combinationhex wrenchand Used to performinternaladjust- TektronixPart No. 003-0489-00
screwdrivertipsforelectronics ments.
use.
5. BananaPlugs Bananaplugwithcap Used to holdresistersand TektronixPart No. 134-0016-01
probehooks. and 134-0198-00
6. ScrewDriver POZIDRIV; length:8 1/2 inch Used to removepanelsand TektronixPart No. 003-0293-00
Pointsize #1, #2 HighVoltageshieldcover.
7. PatchCord BananaPlug-Jackto Banana Used throughoutthe procedure TektronixPart No. 198-5621-00
Plug-Jack and 198-5625-00
8. HighVoltageProbe Voltagerange:0 - 3 kV (DC, Used to examine -2400 V Fluke80K-6
AC); Accuracy:
1 %
9. Test Lead Used throughoutthe procedure FlukeY8131
10. Resistors 25 M
, 0.1 %, 1/2 W To check: TektronixPart No. 067-1337-00
2.5 M
, 0.1 %, 1/2 W S emitteraccuracy
250 k
, 0.1 %, 1/2 W S collectoraccuracyin 500 mA,
1 M
, 5 %, 1/4 W 1 A, 2 A range
10 M
, 5 %, 1/4 W S horizontaldisplaynoise
100
, 5 %, 1/4 W S base inputimpedance
0.025
, 0.1 %, 4 W S stepgeneratoraccuracyin
100 mA and 200 mA range
S stepgeneratorripple
To adjust:
S stepgenerator

5-10 370B Service Manual

 Performance Verification

Table 5-3: Test Equipment (Cont.)

Item Minimum Specification Purpose Example of Applicable Test
Equipment
11. Transistor 2N3904 Used as DUT foracquisitionof TektronixPart No. 151-0190-00
curvedata.
12. Printer Used to checkthe printerinter- CBM, modeliDP3240
face
13. Controller GPIB Support Used to checkthe GPIB a. IBM PC withTektronixGURU
cardrunningBASICA.
b. IBM PC withNationalInstru-
mentsPC2 or PC2A card
runningBASICA.
c. Hewlett-Packard200 or
300 SeriesScientificComputer
running200 or 300 BASIC.
14. FloppyDisk 3.5 inch,2HD Used to storedisplayedcurve
data and instrumentsettings.
15. Test Adapter Used to holdthe DUT. TektronixA1007
16. ExtendedCable Operateinstrumentwithdrawer TektronixPart No. 067-0187-00
unitdetached.

370B Service Manual 5-11

Performance Verification

Power Supply
Equipment Required (see Table 5-3):
H Digital Multimeter
H Test Oscilloscope

A1. Examining Voltage NOTE. The characteristics examined in this step are examples of typical
Deviation and Ripple instrument operation; they are not specifications.

Oscilloscope

To A19

DigitalMultimeter

To A19

See Table 5- 4 To 370B GroundJack

370B settings:
Initialize370B
Test EquipmentSettings:
DigitalMultimeterMode DC Voltage
Test Oscilloscope
VerticalSensitivity 20 mV/div
Time 5 ms/div
Trigger Auto

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 Performance Verification

Examining Voltage Deviation.

1. Connect the digital multimeter to the +5 test point on the A19 LV Supply
board.
2. EXAMINE the digital multimeter reading at the +5 test point and each of the
other power supply test points listed in Table 5-4 for voltage levels within
the given deviation.

Examining Ripple.
3. Disconnect the digital multimeter and connect the test oscilloscope to the
+5 test point.
4. EXAMINE the test oscilloscope display at each of the test points listed in
Table 5-4: for ripple displays within the given deviation.

Removing Setup.
5. Disconnect the test oscilloscope.

Table 5-4: Voltage Regulation and Ripple

Voltage Test Point Deviation Limits (V) Ripple (mV)
+5.2 V +5 +4.99 to +5.41 200
-12 V -12 -11.4 to -12.6 100
+12 V +12 +11.4 to +12.6 100
-6.5 V -6.5 -6.35 to -6.65 50
+6.5 V +6.5 +6.35 to +6.65 50

370B Service Manual 5-13

Performance Verification

A2. Adjusting PLL To A3

DigitalMultimeter

370B settings:
Initialize370B
Test EquipmentSettings:
DigitalMultimeterMode DC Voltage

1. Connect the Digital Multimeter test leads to A-GND test point and 9 pin of
U100.
2. In case that the frequency of line power supply is 50 Hz, adjust R104 PLL
FREQ-1 adjustment on the A3 A/D board for a digital multimeter readout of
2.2
0.1 V.
3. In case that the frequency of line power supply is 60 Hz, adjust R104 PLL
FREQ-1 adjustment on the A3 A/D board for a digital multimeter readout of
3.1
0.1 V.
4. Connect the Digital Multimeter test leads to A-GND test point and 9 pin of
U470.
5. In case that the frequency of line power supply is 50 Hz, adjust R104 PLL
FREQ-2 adjustment on the A3 A/D board for a digital multimeter readout of
2.2
0.1 V.
6. In case that the frequency of line power supply is 60 Hz, adjust R104 PLL
FREQ-2 adjustment on the A3 A/D board for a digital multimeter readout of
3.1
0.1 V.

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 Performance Verification

A3. Checking the +2 V and n {

-2 V Reference
H The +2 V and -2 V Reference is accurate to within 0.001 V.
Adjusting the +2 V and
-2 V Reference (A19 R500
and R516) NOTE. The characteristics examined in this step are examples of typical
instrument operation; they are not specifications.

To A19 (+2V :TP500, - 2V : TP510)

DigitalMultimeter

To 370B GroundJack

370B settings:
Initialize370B
Test EquipmentSettings:
DigitalMultimeterMode DC Voltage

Checking the +2 V Reference.

1. Connect DMM with TP500 on the A19 LV Supply Board.
2. CHECK for a digital multimeter reading of +1.999 V to +2.001 V.
If not within these limits, the following adjustment is necessary.

Adjusting the +2 V Reference.

3. ADJUST +2 V ADJ on the A19 LV Supply Board, for a digital multimeter
reading of +2.000 V.

370B Service Manual 5-15

Performance Verification

Checking the -2 V Reference.

4. Connect DMM with TP510 on the A19 LV Supply Board.
5. CHECK for a digital multimeter reading of -1.999 V to -2.001 V.
If not within these limits, perform part d. Adjusting the -2 V Reference
6. ADJUST -2 V ADJ on the A19 LV Supply Board, for a digital multimeter
reading of -2.000 V.

Removing the Setup.

7. Disconnect the positive lead of the digital multimeter from the test point.

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 Performance Verification

CRT
Equipment Required (see Table 5-3):
H Digital Multimeter
H High Voltage Probe for Digital Multimeter
H Pozidrive Screwdriver with #1 Point

B1.Examining the -2400 V NOTE. The characteristics examined in this procedure are provided as examples
Cathode Supply of typical instrument operation; they are not specifications.

DigitalMultimeter

To 370B GroundJack
HighVoltageProbe

370B settings:
Initialize370B; thenset the followingcontrolsas
indicated.
INTENSITY
NON STORE
STORE/VIEW Fullcounterclockwise
Test Equipmentsettings:
DigitalMultimeterwithHighVoltageProbe
Mode DC Voltage

370B Service Manual 5-17

Performance Verification

Removing the High Voltage Shield.

WARNING. To avoid electric shock hazard, be certain the 370B POWER switch is
set to OFF before removing or replacing the high voltage shield and connecting
the Digital Multimeter to the 370B. Be certain that the Digital Multimeter
ground lead is connected to the 370B ground terminal.

1. Change the following 370B setting:

POWER OFF
2. Use a #1 Pozidrive screwdriver to remove the high voltage shield from the
left side of the 370B. (There are three shields on the left side; remove the
center shield.)

Measuring the Cathode Voltage.

3. Connect the ground lead of High Voltage Probe to chassis ground, and the
High Voltage Probe to TP400 on the A20 HV Regulator Board.
4. Change the following 370B setting:
POWER ON
5. EXAMINE the Digital Multimeter for a reading of -2304 V to -2496 V.

Disconnecting the Meter.

WARNING. To avoid electric shock hazard, be certain the 370B POWER switch is
set to OFF before disconnecting the Digital Multimeter lead and the high
voltage shield.

6. Change the following 370B setting:

POWER OFF
7. Disconnect the High Voltage Probe and Digital Multimeter from the 370B.

Replacing the High Voltage Shield.

8. Replace the high voltage shield.
9. Change the following 370B setting:
POWER ON

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 Performance Verification

B2. Examining CRT Bias {

Adjusting CRT Bias
(A20 R210) NOTE. The characteristics examined in this step are provided as examples of
typical instrument operation to aid in the adjustment of R210; they are not
specifications.

370B settings:
Initialize370B; thenset the followingcontrolsas
indicated.
DISPLAY
Mode NON STORE
COLLECTOR SUPPLY
POLARITY AC

Examining CRT Bias.

1. Change the following 370B settings:

INTENSITY
NON STORE
STORE/VIEW Fullycounterclockwise
READOUT
Cursor Fullycounterclockwise
GRAT ILLUM Fullycounterclockwise

2. EXAMINE the CRT for the displayed spot to be barely visible.

370B Service Manual 5-19

Performance Verification

If the spot is bright or not visible at all, the following adjustment may be
necessary.

Adjusting CRT Bias.

NOTE. R210 can be adjusted through the access hole in the high voltage shield.

3. ADJUST Grid Bias adjustment R210 on the A20 HV Regulator Board until
the CRT spot is barely visible.

B3. Examining {
Astigmatism
Adjusting Astig NOTE. The characteristics examined in this step are provided as examples of
(A18 R420) typical instrument operation to aid in the adjustment of R420; they are not
specifications.

370B settings:
POWER OFF
FOCUS Fullycounterclockwise

1. While pressing the FAST/SHIFT button, set the 370B POWER switch to
ON. This displays the Frame Test Pattern on the CRT.

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 Performance Verification

Examining Astigmatism.
2. Change the following 370B settings:

INTENSITY
NON STORE
STORE/VIEW Largestpossibledisplayed
centerspot
READOUT
Cursor Fullycounterclockwise

3. EXAMINE the center spot for a circular shape. If the center spot is not
circular, the following adjustment may be necessary.

Adjusting Astigmatism.
4. ADJUST ASTIG adjustment R420 on the A18 CRT Output Board for a
circular spot shape.
5. Change the following 370B settings:

FOCUS Clockwiseforsmallest
possiblespot
INTENSITY
NON STORE
STORE/VIEW NormalViewing
READOUT
Cursor NormalViewing

6. EXAMINE the CRT for the Frame Test Pattern to be similarly in focused.
If the Frame Test Pattern is not similarly focusing, the following adjustment
may be necessary.
7. READJUST ASTIG adjustment R420 on the A18 CRT Output Board for
slightly compromise between the center dot and the outer frame.

Removing the Setup.

8. Press the FAST/SHIFT key to exit the Frame Test Pattern.

370B Service Manual 5-21

Performance Verification

B4. Examining NON NOTE. The characteristics examined in this step are examples of typical
STORE/STORE/VIEW instrument operation; they are not specifications.
INTENSITY Operation

Disk Slot

370B settings: FloppyDisk

Initializethe 370B; thenset the
followingcontrolsas indicated.

DISPLAY
VERTICAL STEP GEN
OUTPUTS ENABLED
VARIABLECOLLECTOR 100 %
SUPPLY
ProtectiveCover Closed
INTENSITY
NON STORE
STORE/VIEW NormalViewing

NOTE. Be sure to use a formatted floppy disk to perform this procedure.

Entering waveform data

Entering waveform data.

1. Set the MEMORY number to 2, using the up MEMORY button.
2. Press ENTER. Examine the display for the “ENTER COMPLETE”
message.

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 Performance Verification

Examining NON STORE Intensity.

3. Change the following 370B setting:

DISPLAY
Mode NON STORE
VARIABLECOLLECTOR about50 %
SUPPLY

4. EXAMINE the CRT for a continuous increase in NON STORE waveform

brightness as the NON STORE/STORE/VIEW INTENSITY control is
turned from fully counterclockwise to fully clockwise.

Examining STORE Intensity.

5. Change the following 370B setting:

DISPLAY
Mode STORE

6. EXAMINE the CRT for a continuous increase in STORE waveform

brightness when the NON STORE/STORE/VIEW INTENSITY control is
turned from fully counterclockwise to fully clockwise.

Examining VIEW Intensity.

7. Change the following 370B setting:

DISPLAY
Mode VIEW

8. EXAMINE the CRT for a continuous increase in VIEW waveform bright-

ness when the NON STORE/STORE/VIEW INTENSITY control is turned
from fully counterclockwise to fully clockwise.

370B Service Manual 5-23

Performance Verification

B5. Examining REF NOTE. The characteristics examined in this step are examples of typical
INTENSITY Operation instrument operation; they are not specifications.

370B settings:
Initialize370B

1. Press the REF button.

2. Change the following 370B setting:

DISPLAY INVERT ON

3. EXAMINE the CRT for a continuous increase in brightness of the viewed

trace as the REF INTENSITY control is turned from full counterclockwise to
fully clockwise.

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 Performance Verification

B6. Examining NOTE. The characteristics examined in this step are examples of typical
READOUT/CURSOR instrument operation; they are not specifications.
INTENSITY Operation

370B settings:
Initializethe 370B; thenset the followingcontrolas
indicated.
CURSOR
Mode WINDOW

1. EXAMINE the display for a continuous increase in readout and cursor

brightness as the READOUT/CURSOR INTENSITY control is turned from
fully counterclockwise to fully clockwise.
2. Change the following 370B setting:

INTENSITY
READOUT
CURSOR Normalviewinglevel

370B Service Manual 5-25

Performance Verification

Display
Equipment Required (see Table 5-3)
H Digital Multimeter

C1. Examining Calibrator NOTE. The characteristics examined in this step are examples of typical
Voltage instrument operation;they are not specifications.

To A5TP658

DigitalMultimeter

To A5TP80

370B settings:
Initializethe 370B
Test Equipmentsettings:
DigitalMultimeterMode DC Voltage

Examining Horizontal CAL ZERO.

1. Change the following 370B setting:

DISPLAY
Mode CAL ZERO

CAL ZERO is initiated by pressing the NON STORE button while holding
down the FAST/ SHIFT button.

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 Performance Verification

2. EXAMINE the digital multimeter for a reading between -0.995 V and

-1.005 V

Examining Horizontal CAL FULL.

3. Change the following 370B setting:

DISPLAY
Mode CAL FULL

CAL FULL is initiated by pressing the REF button while holding down the
FAST/SHIFT button.
4. EXAMINE the digital multimeter for a reading between +0.995 V and
+1.005 V.
5. Disconnect the digital multimeter positive lead from TP658.

Examining Vertical CAL FULL.

6. Connect the digital multimeter positive lead to TP648 on the A5 Display
Control Board.
7. EXAMINE the digital multimeter for a reading between + 0.995 V and
+1.005 V.

Examining Vertical CAL ZERO.

8. Change the following 370B setting:

DISPLAY
Mode CAL ZERO

9. EXAMINE the digital multimeter for a reading between -0.995 V and

-1.005 V.

370B Service Manual 5-27

Performance Verification

Removing the Setup.

10. Change the following 370B setting:

DISPLAY
Mode CAL OFF

CAL OFF is initiated by pressing the STORE button while holding down
the FAST/SHIFT button.
11. Disconnect the digital multimeter from TP648 and TP80.

C2. Adjusting V Zero {

and H Zero
(A3R600 and A3R590) NOTE. The characteristics examined in this step are provided as examples of
typical instrument operation to aid in the adjustment of R600 and R590; they are
not specifications.

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
COLLECTOR SUPPLY AC
POLARITY
CURSOR
Mode DOT
DISPLAY
Mode CAL ZERO

CAL ZERO is initiated by pressing the NON STORE button while holding
down the FAST/SHIFT button.

5-28 370B Service Manual

 Performance Verification

Determining if Adjustment is Necessary.

1. Examine the vertical CURSOR readout for a reading that does not exceed

0.06 A and the horizontal CURSOR readout for a reading that does not
exceed 0.06 V.
If the CURSOR readouts are not within these limits, the following adjust-
ment is necessary.

Adjust H Zero and V Zero.

2. Press INVERT button inDISPLAY MENU.
3. Adjust R590 so that the horizontal CURSOR readout for a reading may not
change.
Adjust R600 so that the vertical CURSOR readout for a reading may not
change.

C3. Adjusting Storage {

Gain (A3R610)
NOTE. The characteristics examined in this step are provided as examples of
typical instrument operation to aid in the adjustment of R610; they are not
specifications.

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
Mode CAL ZERO
CURSOR
Mode DOT

370B Service Manual 5-29

Performance Verification

CAL ZERO is initiated by pressing the NON STORE button while holding
down the FAST/SHIFT button.

Determining Adjustment is Necessary.

1. EXAMINE the vertical and horizontal CURSOR readouts for readings of
0.00
0.06.
If the CURSOR readouts are not within these limits, the following adjust-
ment is necessary.

Adjusting Storage Gain.

2. ADJUST Storage Gain adjustment R610 on the A3 A/D Board for Vertical
and Horizontal CURSOR readouts of 0.00.

Examining Storage Gain for CAL FULL.

3. Change the following 370B setting:

DISPLAY
Mode CAL FULL

CAL FULL is initiated by pressing the REF button while holding down the
FAST/SHIFT button.
4. EXAMINE the vertical and horizontal CURSOR readout for a reading of
20.00
0.36.

Removing the Setup.

5. Change the following 370B setting:

DISPLAY
Mode CAL OFF

CAL OFF is initiated by pressing the STORE button while holding down
the FAST/SHIFT button.

5-30 370B Service Manual

 Performance Verification

C4. Checking n {
Orthogonality and
Specifications:
Geometry
H Orthogonality is 90_ within 0.3_.
Examining Store Position,
Non Store Gain, and D/A H Geometry includes two categories: (1) Tilt or bowing is no more than 0.5
Gain minor division. (2) Keystone effect is no more than 0.75 minor division.

Adjusting SX Position (A5 NOTE. Characteristics in EXAMINE steps are provided as examples of typical
R508), SY Position (A5 instrument operation to aid in adjustment; they are not specifications.
R528), D/A Gain (A4
R842), X Gain (A5 R554), Y
Gain (A5 R574),
Orthogonality (A5 R80),
Geom (A18 R410)

370B settings: NON

Initiating the Test Pattern.

1. Change the following 370B setting:

POWER OFF

2. Hold the FAST/SHIFT button depressed and set the 370B POWER to ON.
This initiates the diagnostic routine. The corporate logo first appears,
followed by the display test pattern shown in Figure 5-1.

370B Service Manual 5-31

Performance Verification

Figure 5-1: Diagnostic test pattern display

The test pattern consists of the Frame Test Pattern overlaid over the Dot Test
Pattern.
3. Turn the GRAT ILLUM control fully clockwise for maximum brightness.
4. Set the Frame Test Pattern to the same intensity as the graticule using the
Intensity READOUT/CURSOR control and set the Dot Test Pattern slightly
brighten using the intensity NON STORE/STORE/VIEW INTENSITY
control.

Examining Store Position.

5. EXAMINE the display to determine whether the center cross mark of the
Frame Test Pattern aligns with the center dot of the Dot Pattern.
If the pattern centers do not align, the following adjustments are necessary.

Adjusting SY Position and SX Position.

The SX and SY Position controls change the Frame Test Pattern position without
affecting the Dot Test Pattern position.
6. ADJUST SY Position adjustment R528 and SX Position adjustment R508
on the A5 Display Control Board so that the center cross mark of the Frame
Test Pattern conforms to the center dot of the Dot Pattern (not the center of
the graticule).

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 Performance Verification

Examining and Adjusting D/A Gain.

7. EXAMINE the display to determine whether the outer eight dots of the Dot
Pattern are located between the inner frame and outer frame of the Frame
Test Pattern.
If the location is not correct, the following adjustment is necessary.
8. ADJUST D/A Gain adjustment R842 on the A4 Digital Display Board to
position the outer eight dots between the inner frame and outer frame of the
Frame Test Pattern.
D/A Gain adjusts the size of the Frame Test Pattern without changing the
Dot Test Pattern size.

Checking and Adjusting the Display. The Dot and Frame Test Pattern are visual
aids for display alignment. Positioning, straightening and sizing of the display
involves several adjustments. Three of these adjustment, GEOMETRY,TRACE
ROTATION, and ORTHOGONALITY are interactive.
H GEOMETRY adjusts the curvature of the sides, top and bottom of the test
pattern:
H TRACE ROTATION tilts the test pattern about a pivot point approximately
2 1/2 divisions from the right side of the graticule on the horizontal center
line.
H ORTHOGONALITY changes the test pattern shape from rhombic to
rectangular.
H X-GAIN and Y-GAIN change the test pattern from rectangular to square.
H Front-panel POSITION controls change the position of the whole display.

Checking Orthogonality.
9. Change the following 370B settings:

POSITION controls
Verticaland Horizontal Positionthe centerdotto graticule
center.
TRACE ROTATION Positionthe threeintermediate
horizontaldotson the centerhorizon-
tal graticuleline.

370B Service Manual 5-33

Performance Verification

10. CHECK that the three intermediate vertical dots conform to the center
vertical graticule line within 0.5 minor division.
If the dots do not conform, the following adjustment is necessary.

Adjusting Orthogonality.
11. ADJUST Orthogonality adjustment R80 on the A5 Display Control Board so
that the three intermediate vertical dots conform to the center vertical
graticule line.

Examining Non-Store Gain.

12. EXAMINE the display to determine if the Dot Pattern’s outer eight dots are
positioned within the inner and outer frame patterns.
If the positioning is not correct, the following adjustment is necessary.

Adjusting X-Gain and Y-Gain.

13. ADJUST X-Gain adjustment R554 and Y-Gain adjustment R574 on the A5
Display Control Board to position the Dot Pattern’s outer eight dots within
the inner and outer Frame Patterns.

Checking and Adjusting Geometry.

14. Change the following 370B settings:

POSITION controls
Verticaland Horizontal Positionthe centerdotof the Dot
Patternat graticulecenter.

15. CHECK the Frame Pattern for ≤0.5 minor division of bowing and
≤0.75 minor division of keystone effect. If the bowing and keystone effect
are not within these limits, the following adjustment may be necessary.
16. ADJUST Geometry adjustment R410 on the A18 CRT Output Board (if
necessary) for minimum display bowing.

Examining the Display for Adjustment Interaction.

17. EXAMINE the display for all dots to be between the outer frame and inner
frame of the Frame Test Pattern, within 0.5 minor division.
If not, repeat parts 10 through 14.

5-34 370B Service Manual

 Performance Verification

18. EXAMINE the display for the graticule periphery to be between the outer
frame and inner frame of the frame test pattern, within 0.5 minor division.
If not, repeat parts 10 through 14.
19. EXAMINE the display for the center dot to be at graticule center, within
0.5 minor division.

Removing the Test Pattern.

20. Press the FAST/SHIFT button to exit the diagnostic routine.

C5. Checking DISPLAY n

INVERT Accuracy
Specification:
H DISPLAY INVERT for Digital Storage Vertical and Horizontal acquisition is
accurate to within 0.04 of VERT/DIV or HORIZ/DIV setting.

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
Mode CAL ZERO
CURSOR
Mode DOT

CAL ZERO is initiated by pressing the NON STORE button while holding
down the FAST/SHIFT button.
1. Change the following 370B setting:

DISPLAY
INVERT ON

370B Service Manual 5-35

Performance Verification

2. The indicator above the INVERT button will light.

3. Check that the spot moves from lower left corner to the upper right corner of
the graticule and the vertical CURSOR readout and horizontal CURSOR
readout are 0.00
0.08.

C6. Checking Display n

Offset Accuracy
Specifications:
H For Digital Storage Vertical and Horizontal Acquisition, the center-line
display can be vertically and horizontally offset up to ten divisions in
0.1 division steps.
H Display Offset is accurate to within {1.5 % of the offset (in divisions)
+0.01 division of the setting}.

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
Mode CAL ZERO
CURSOR
Mode DOT
POSITION
Mode DISPLAY

Hold down the FAST/SHIFT button and press the NON STORE button to enter
the CAL ZERO mode.

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 Performance Verification

Checking Positive Offset.

1. EXAMINE the display, as the right Position Control button is pressed, for
the spot to move continuously from lower left corner to lower right corner.
2. EXAMINE the display, as the up Position Control button is pressed, for the
spot to move continuously from lower right corner to upper right corner.
3. CHECK the vertical and horizontal CURSOR readout within
0.32 V.

Checking Negative Offset.

4. Change the following 370B setting:

COLLECTOR SUPPLY
POLARITY -
POSITION Simultaneouslypressthe up and
downPositionControlbuttons,then
simultaneouslypressthe leftand
rightPositionControlbuttons.

5. EXAMINE the display, as the left Position Control button is pressed, for the
spot to move continuously from upper right corner to upper left corner.
6. EXAMINE the display, as the down Position Control button is pressed, for
the spot to move continuously from upper left corner to lower left corner.
7. CHECK the vertical and horizontal CURSOR readouts within
0.32 V.

370B Service Manual 5-37

Performance Verification

C7. Adjusting Looping {

Compensation (A10R139,
A10R224, A35R500, NOTE. The characteristics examined in this step are provided as examples of
A35R501, A35R502, typical instrument operation to aid in the adjustment of R139, R224, R500,
A35R503, A35R504) R501, R502, R503, R504; they are not specifications.
The accuracy of the vertical displayed noise may be affected by these adjust-
ments. See E7.

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
Mode NON STORE
VERTICAL CURRENT/DIV 1 A COLLECTOR
HORIZONTAL VOLTS/DIV 200 V COLLECTOR
COLLECTOR SUPPLY 2000 V
MAX PEAK VOLTS
POSITION DISPLAY
OUTPUTS ENABLED
VARIABLECOLLECTOR 100 %
SUPPLY
MAX PEAK POWER WATTS 50 W
ProtectiveCover Closed

1. Press the “up” Position Control button to move the trace to graticule center.

NOTE. Following adjustments from 2 to f are preliminary adjustment.

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 Performance Verification

Preliminary Adjustment.
2. Preset the following 370B adjustments:

A10R139 (TAN-DELTA) center

A10R224 (LOOP GAIN) center

A cutout in the right siderail provides adjustment access.

A cutout in the right side of the guard box provides adjustment access.
3. ADJUST R503 2000 V LOOPING adjustment on the A35 Looping board for
overlapping of the loop using LOOPING COMPENSATION control.
4. ADJUST R500 LOOPING BALANCE adjustment on the A35 Looping
board to minimize the vertical projection of the left portion of the loop using
the LOOPING COMPENSATION control.
5. ADJUST R139 TAN-DELTA on the A10 Sense board to align the display
with the horizontal graticule line using the LOOPING COMPENSATION
control.
6. Change the Max Peak Power Watts from 50 W to 0.08 W.
7. ADJUST R224 LOOPING GAIN adjustment on the A10 Sense board to
minimize the vertical projection of the left portion of the loop using the
LOOPING COMPENSATION control.
8. Change the Max Peak Power Watts from 0.08 W to 50 W.
9. Repeat steps 3 through 7.

Examining 2000 V LOOPING.

10. Change the following 370B settings:

DISPLAY
HORIZONTAL VOLTS/DIV 200 V COLLECTOR
COLLECTOR SUPPLY 2000 V
MAX PEAK VOLTS
VARIABLECOLLECTOR 100 %
SUPPLY
LOOPING COMPENSATION Minimumtracewidth

370B Service Manual 5-39

Performance Verification

11. EXAMINE the left end of the displayed trace for optimum overlay of the
loop, and the right side to run parallel with the horizontal graticule lines.
If the overlay is not optimum, and the trace does not parallel the horizontal
graticule lines, the following adjustment is necessary.

Adjusting 2000 V LOOPING.

12. ADJUST R503 2000 V LOOPING adjustment on the A35 Looping board for
optimum overlay of the left portion of the loop. See Figure 5-2.

Correct

Incorrect

Figure 5-2: Looping compensation display

A cutout in the left side of the guard box provides adjustment access.

5-40 370B Service Manual

 Performance Verification

Adjusting LOOP BALANCE.

13. ADJUST R500 LOOP BALANCE on the A35 Looping board to align the
display with the horizontal graticule line, using the LOOPING COM-
PENSATION control.
If necessary, repeat steps 12 and 13.

Adjusting TAN-DELTA.
14. Change the following 370B setting:

COLLECTOR SUPPLY
MAX PEAK POWER 50 W
WATTS

15. ADJUST TAN-DELTA R139 on the A10 Sense board to align the display
with the horizontal graticule line, using the LOOPING COMPENSATION
control.

Readjusting LOOP BALANCE.

16. Change the following 370B settings:

COLLECTOR SUPPLY
MAX PEAK POWER 0.08 W
WATTS

17. READJUST R500 LOOP BALANCE on the A35 Looping Board to align
the display with the horizontal graticule line, using the LOOPING COM-
PENSATION control.
If necessary, repeat steps 14 through 17.

370B Service Manual 5-41

Performance Verification

Examining 400 V LOOPING.

18. Change the following 370B settings:

DISPLAY
HORIZONTAL VOLTS/DIV 50 V COLLECTOR
COLLECTOR SUPPLY 400 V
MAX PEAK VOLTS
VARIABLECOLLECTOR 100 %
SUPPLY
LOOPING COMPENSATION Minimumtracewidth

19. EXAMINE the left end of the displayed trace for optimum overlay of the
trace.
If the left end of the trace doesn’t overlay correctly, the following adjustment is
necessary.

Adjusting 400 V LOOPING.

20. ADJUST R501 400 V LOOPING adjustment on the A35 Looping board for
optimum overlay of the left end of the trace.

Examining 80 V LOOPING.
21. Change the following 370B settings:

DISPLAY
HORIZONTAL VOLTS/DIV 10 V COLLECTOR
COLLECTOR SUPPLY 80 V
MAX PEAK VOLTS
VARIABLECOLLECTOR 100 %
SUPPLY
LOOPING COMPENSATION Minimumtracewidth

22. EXAMINE the left portion of the displayed trace for optimum overlay (see
Figure 5-2). If the overlay is not optimum, the following adjustment is
necessary.

Adjusting 80 V LOOPING.
23. ADJUST R502 80 V LOOPING adjustment on the A35 Looping board for
optimum overlay of the left portion of the trace.

5-42 370B Service Manual

 Performance Verification

Examining 16 V LOOPING.
24. Change the following 370B settings:

DISPLAY
HORIZONTAL VOLTS/DIV 2 V COLLECTOR
COLLECTOR SUPPLY 16 V
MAX PEAK VOLTS
VARIABLECOLLECTOR 100 %
SUPPLY
LOOPING COMPENSATION Minimumtracewidth

25. EXAMINE the left portion of the displayed trace for optimum overlay of the
trace (see Figure 5-2).
If the overlay is not optimum, the following adjustment is necessary.

Adjusting 16 V LOOPING.
26. ADJUST R504 16 V LOOPING adjustment on the A35 Looping board for
optimum overlay of the left portion of the trace.

370B Service Manual 5-43

Performance Verification

Horizontal
Equipment Required (see Table 5-3):
H Calibrator (DC Voltage Source)
H 1 M
, 5 %, 0.25 W Resistor
H 10 M
, 5 %, 0.25 W Resistor

D1. Adjusting H Balance NOTE. The characteristics examined in this step are provided as examples of
(A10R460) typical instrument operation to aid in the adjustment of R460; they are not
specifications.

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
COLLECTOR SUPPLY AC
POLARITY
MAG X10 On
CURSOR
Mode DOT
OUTPUTS ENABLED
LEFT-RIGHT-STANDBY LEFT or RIGHT
ProtectiveCover Closed

5-44 370B Service Manual

 Performance Verification

Determining if Adjustment Is Necessary.

1. EXAMINE the horizontal CURSOR readout for a reading of 0,
60 mV.
If the reading is not within these limits, the following adjustment is
necessary.

Adjusting H Balance.
2. ADJUST H Balance adjustment R460 on the A10 Sense Board for a
horizontal CURSOR readout of 0 mV.
A cutout in the right side rail provides adjustment access.

D2. Checking horizontal n

MAG X10 Accuracy
Specification:
H OFFSET with MAG set to X10 is accurate to within (1.5 % of the readout
+0.3 division of the setting).

DigitalMultimeter

To LeftBase
To LeftEmitter

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
MAG X10
COLLECTOR SUPPLY AC
POLARITY
DISPLAY
HORIZONTAL 200 mV BASE/EMITTER

370B Service Manual 5-45

Performance Verification

STEP GENERATOR
Mode VOLTAGE
STEP AMPLITUDE 1V
OFFSET 4V
NUMBER OF STEPS 0
CURSOR DOT
POSITION
Mode DISPLAY
OUTPUTS ENABLED
LEFT-RIGHT-STANDBY LEFT
ProtectiveCover Closed
Test Equipmentsetting
DigitalMultimeter
Mode DC Voltage

Checking horizontal MAG X10 Accuracy.

1. CHECK that the difference between horizontal CURSOR readout and
Digital Multimeter reading is within
120 mV.

Removing the Setup.

2. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

3. Remove the digital multimeter leads from the 370B.

5-46 370B Service Manual

 Performance Verification

D3. Checking n
HORIZONTAL
Specifications:
BASE/EMITTER Accuracy
and Range in STORE H The BASE/EMITTER settings are accurate to within 1.5 % of the readout
Mode +0.05 division of the setting.

DC VoltageSource

To LeftBase
To LeftEmitter

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
HORIZONTAL 50 mV BASE/EMITTER
CURSOR
Mode DOT
CONFIGURATION BASE OPEN (EXT)
OUTPUTS ENABLED
ProtectiveCover Closed
Test Equipmentsetting
Calibrator
Output 0.00 V

NOTE. Disregard the flashing cursor on the 370B display.

370B Service Manual 5-47

Performance Verification

Checking Base/Emitter Accuracy.

1. Change the following 370B setting:

LEFTLEFT-RIGHT-STANDBY LEFT

2. CHECK that the horizontal CURSOR readout is within the CURSOR

Readout limits for each HORIZONTAL (BASE/EMITTER) VOLTS/DIV
and DC Voltage setting listed in Table 5-5.
There are two DC Voltage values given for each HORIZONTAL VOLTS/
DIV setting in Table 5-5; check for both.
To check the 2 V and 5 V Horizontal Volts/Div settings, push the Operate
button on the Voltage Source.

Table 5-5: Base/Emitter Voltage Accuracy

HORIZONTAL VOLTS/DIV Calibrator DC Voltage Horizontal CURSOR
Setting Readout
50 mV 0.000 mV
2.5 mV
450.0 mV 440.8 mV to 459.2 mV
200 mV 0.000 mV
10 mV
1800 mV 1763 mV to 1837 mV
2V 0.00 V
0.10 V
18.00 V 17.63 V to 18.37 V

Removing the Setup.

3. Change the following Test Equipment setting:

Calibrator
Output Standby

4. Disconnect the Calibrator leads from the 370B.

5-48 370B Service Manual

 Performance Verification

D4. Checking n
HORIZONTAL
Specifications:
COLLECTOR Voltage
Accuracy and Range in H The HORIZONTAL COLLECTOR settings are accurate to within 1.5 % of
STORE Mode the readout +0.05 division of the setting.

DC VoltageSource

To LeftCollector

To LeftEmitter

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
HORIZONTAL 50 mV COLLECTOR
COLLECTOR SUPPLY MAX 400 VOLT/DIV
PEAK VOLTS
CURSOR
Mode DOT
ProtectiveCover Closed
LEFT-RIGHT-STANDBY LEFT
Test Equipmentsetting
Calibrator
Output 0.00 V DC

WARNING. Extreme caution must used when performing the following step due to
the dangerous potentials present at the input of the 370B.
The protective cover should be installed.

370B Service Manual 5-49

Performance Verification

Checking Collector Voltage Accuracy.

1. CHECK that the horizontal CURSOR readout is within the CURSOR
Readout limits for each HORIZONTAL CURRENT VOLTS/DIV and DC
Voltage setting listed in Table 5-6.
There are two DC Voltage values given for each HORIZONTAL VOLTS/
DIV setting in Table 5-6: Check for both.

Removing the Setup.

2. Change the following 370B setting:

LEFT-RIGHT-STANDBY SATNDBY

3. Change the following test equipment setting:

Calibrator
Output 0.00 V

WARNING. Be certain that the output of the Calibrator is set to zero or Standby
before connecting or disconnecting the test leads.

4. Disconnect the Calibrator leads from the 370B.

Table 5-6: Collector Voltage Accuracy

HORIZONTAL VOLTS/DIV Calibrator DC Voltage Horizontal CURSOR
Setting Readout
50 mV 0.000 mV
2.5 mV
450.0 mV 440.8 mV to 459.2 mV
1V 0.00 mV
50 mV
9V 8.82 V to 9.18 V
20 V 0.00 mV
1.0 V
180 V 176.3 V to 183.7 V
100 V 0.00 mV
5 V
900.00 V 881.5 V to 918.5 V
500 V 0.00 mV
25 V
1000 V 960 Vto 1040 V

5-50 370B Service Manual

 Performance Verification

D5. Checking Base Input n

Impedance
Specifications:
H Input impedance is at least 100 M
.

DC VoltageSource

To LeftEmitter

10 M
, 5 %,
0.25 W Resistor
To LeftBase

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
CONFIGURATION BASE OPEN (EXT)
DISPLAY
HORIZONTAL 2 V BASE/EMITTER
CURSOR
Mode DOT
OUTPUTS ENABLED
LEFT-RIGHT-STANDBY LEFT
ProtectiveCover Closed
Test Equipmentsetting
Calibrator
Output 20 V DC

Checking Input Impedance.

1. CHECK that the horizontal CURSOR reading is more than 18.3 V.

370B Service Manual 5-51

Performance Verification

Removing the Setup.

2. Set the Calibrator output to 0 V.
3. Remove the resistor and Calibrator.

D6. Checking Horizontal n

Displayed Noise
Specifications:
H Displayed noise (peak-peak) in COLLECTOR VOLTS is <0.02 % of MAX
PEAK VOLTS setting.

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
COLLECTOR SUPPLY PO- AC
LARITY
MAX PEAK POWER WATTS 220
VARIABLECOLLECTOR 0%
SUPPLY
MAG X10 On
DISPLAY
Mode NON STORE
HORIZONTAL VOLT/DIV 5 mV COLLECTOR
OUTPUTS ENABLED
ProtectiveCover Closed

5-52 370B Service Manual

 Performance Verification

Checking Noise at COLLECTOR VOLTS.

1. CHECK that the spot width is no more than 3.2 mV (3.2 minor divisions)
peak-peak (see Table 5-7).

Table 5-7: Displayed Horizontal Noise

COLLECTOR SUPPLY MAX PEAK VOLTS Horizontal Spot Width (Noise)
Collector Volts
16 3.2 mV (3.2 min.div)
80 16 mV (3.2 div)
400 80 mV (16 div)(1.6 div; 50 mV / DIV)

2. Change the following 370B setting:

MAX PEAK VOLTS 80

3. CHECK that the spot width is no more than 16 mV (3.2 divisions) peak-
peak (see Table 5-7).
4. Change the following 370B setting:

MAG X10 Off

MAX PEAK VOLTS 400

5. CHECK that the spot width is no more than 80 mV (1.6 divisions) peak-
peak (see Table 5-7).

REMOVING THE SETUP.

6. Disconnect the resistor.

370B Service Manual 5-53

Performance Verification

Vertical
Equipment Required (see Table 5-3):
H Calibrator (Precision Voltage and Current Source)
H Resistor: 2.5 M
, 0.1 %, 0.5 W
H Resistor: 250 k
, 0.1 %, 0.5 W
H Resistor: 25 M
, 0.1 %, 0.5 W
H Resistor: 0.025
, 0.1 %, 4 W

E1. Adjusting V Balance {

(A10R250)
NOTE. The characteristics examined in this step are provided as examples of
typical instrument operation to aid in the adjustment of R250; they are not
specifications.

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
COLLECTOR SUPPLY AC
POLARITY
MAG X10 On
CURSOR
Mode DOT
LEFT-RIGHT-STANDBY LEFT or RIGHT
ProtectiveCover Closed
OUTPUTS ENABLED

5-54 370B Service Manual

 Performance Verification

Determining if Adjustment is Necessary.

7. Rotate the LOOPING COMPENSATION control fully clockwise, then
counterclockwise.
8. EXAMINE the vertical CURSOR readout for a reading less than 60 mA.
If the readout is not within these limits, the following adjustment is
necessary.

Adjusting V Balance.
9. ADJUST V Balance adjustment R250 on the A10 Sense Board; for a vertical
CURSOR readout to 0 mA.
The adjustment is accessible through the right lower rail cutout.

E2. Adjusting Looping {

Balance (A10R238)
NOTE. The characteristics examined in this step are provided as examples of
typical instrument operation to aid in the adjustment of R238; they are not
specifications.

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
COLLECTOR SUPPLY AC
POLARITY
MAG X10 On
CURSOR
Mode DOT

370B Service Manual 5-55

Performance Verification

LEFT-RIGHT-STANDBY LEFT or RIGHT

ProtectiveCover Closed
OUTPUTS ENABLED

Determining if Adjustment is Necessary.

1. Set the LOOPING COMPENSATION control fully clockwise, then
counterclockwise.
2. Note the vertical CURSOR readout.
3. Set the LOOPING COMPENSATION control fully clockwise.
4. Note the vertical CURSOR readout.
5. EXAMINE the difference of the vertical CURSOR readout between noted
part 2 and 4.
If the difference of readout is not within 20 mA, the following adjustment
may be necessary.
It is not specification.

Adjusting Looping Compensation.

6. ADJUST Looping Balance adjustment R238 on the A10 Sense Board for a
vertical CURSOR readout as noted in part 2. Return the LOOPING
COMPENSATION control to fully counterclockwise.

5-56 370B Service Manual

 Performance Verification

E3. Adjusting Leakage {

Compensation (A10R270)
NOTE. The characteristics examined in this step are provided as examples of
typical instrument operation to aid in the adjustment of R270; they are not
specifications.

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
COLLECTOR SUPPLY + LEAKAGE
POLARITY
DISPLAY 1 nA EMITTER
VERTICAL CURRENT/DIV
CURSOR
Mode DOT
POSITION
Mode DISPLAY
OUTPUTS ENABLED
ProtectiveCover Closed

Determining if Adjustment is Necessary.

1. Press the up Position Control button to position the dot center horizontal
graticule line.
2. EXAMINE the vertical CURSOR readout for a reading within 1.03 nA.
If the readout is not within these limits, the following adjustment may be
necessary. Otherwise, proceed to the next step.

370B Service Manual 5-57

Performance Verification

Adjusting Leakage Compensation.

3. ADJUST Leakage Compensation adjustment R270 on the A10 Sense Board;
for a Vertical CURSOR readout of 0.00 nA.

E4. Checking vertical MAG n

X10 Accuracy
Specification:
H OFFSET with MAG set to X10 is accurate to within (1.5 % of the readout
+0.3 division of the setting).

DMM

To LeftBase

To LeftCollector

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
COLLECTOR SUPPLY
POLARITY AC
MAX PEAK POWER 220
WATTS
MAX X10 On
DISPLAY
HORIZONTAL 50V COLLECTOR
VERTICAL 1mA COLLECTOR
STEP GENERATOR
Mode CURRENT
STEP AMPLITUDE 10mA
OFFSET - 100mA
NUMBER OF STEPS 0
CURSOR DOT

5-58 370B Service Manual

 Performance Verification

POSITION
Mode DISPLAY
LEFT-RIGHT-STANDBY LEFT
OUTPUTS ENABLED
ProtectiveCover Closed
Test Equipmentsetting
DigitalMultimeter
Mode DC Current

Checking vertical MAG X10 Accuracy.

1. Set the the following 370B setting:

POSITION Use the “down”Positioncontrol

buttonto set the spotnear the
verticalcen ter.

2. CHECK that the difference between the vertical CURSOR readout and the
Digital Multimeter reading is within
1.8 mA.

Removing the Setup.

3. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

4. Remove the digital multimeter leads from the 370B.

370B Service Manual 5-59

Performance Verification

E5. Checking EMITTER n

CURRENT Accuracy and
Specifications:
Range in STORE Mode
H STORE mode EMITTER CURRENT/DIV settings are accurate to within
1.5% of the readout +0.05 division of the setting +1 nA.

DC VoltageSource

See Table 5- 4
To 370B Groundjack
To EXT BASE or EMITTER

To LeftBASE To LeftEMITTER

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
COLLECTOR SUPPLY
POLARITY + LEAKAGE
DISPLAY
HORIZONTAL 500 V COLLECTOR
VERTICAL 1 nA EMITTER
CURSOR DOT
POSITION
MODE DISPLAY
OFFSET HORIZONTAL 1.0 DIV
CONFIGURATION BASE OPEN (EXT)
OUTPUTS ENABLED
ProtectiveCover Closed
Test Equipmentsetting
Calibrator
Output 0.000 V

5-60 370B Service Manual

 Performance Verification

Checking 1 nA
1. CHECK that the vertical CURSOR readout is within the limits listed in
Table 5-8 for each combination of VERTICAL CURRENT/DIV and
Calibrator settings.

Checking 20 nA
2. CHECK that the vertical CURSOR readout is within the limits listed in
Table 5-8 for each combination of VERTICAL CURRENT/DIV and
Calibrator settings.

Checking 500 nA
3. CHECK that the vertical CURSOR readout is within the limits listed in
Table 5-8 for each combination of VERTICAL CURRENT/DIV and
Calibrator settings.

Removing the Setup.

4. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

5. Disconnect the voltage source and resistor from the 370B.

Table 5-8: Emitter Current Accuracy

VERTICAL CUR- Calibrator DC Calibrator DC Vertical CURSOR
RENT/DIV Setting Voltage Current Readout
1 nA (shuntresistor 0.000 V 0.00
1.05 nA
25M
) 225 mV 9nA 7.82nA to 10.18 nA
20 nA(shuntresistor 0.000 V 0.00
2.0 nA
2.5M
) 450 mV 180nA 175.3 nA to 184.7 nA
500 nA(shuntresistor 0.000 V 0.00
26 nA
250k
) 1125 mV 4500nA 4407 nA to 4593 nA

370B Service Manual 5-61

Performance Verification

E6.a. Checking n
COLLECTOR CURRENT
Specifications:
Accuracy and Range in
STORE Mode H STORE mode COLLECTOR CURRENT/DIV settings are accurate to within
1.5 % of the readout +0.05 division of the setting.

DC CurrentSource

To LeftCollector

To LeftEmitter

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
VERTICAL 1 A CURRENT/DIV
HORIZONTAL 500 V VOLT/DIV
COLLECTOR SUPPLY
POLARITY -
MAX PEAK POWER WATTS 220
CURSOR
Mode DOT
LEFT-RIGHT-STANDBY LEFT
ProtectiveCover Open
Test Equipmentsetting
Calibrator
Output 0.00 A

1. CHECK that each setting of the VERTICAL CURRENT/DIV control listed

in Table 5-9 produces a vertical CURSOR readout within the limits given
for a Calibrator setting of 0.00 A (open circuit).

5-62 370B Service Manual

 Performance Verification

2. Change the following test equipment setting:

Calibrator
Output 9.00 A

3. CHECK that each combination of VERTICAL CURRENT/DIV and

Calibrator settings listed in Table 5-9 produces a vertical CURSOR readout
within the given limits.

Removing the Setup.

4. Change the following Test Equipment setting:

Calibrator
Output 0.00 A

5. Disconnect the DC current source from the 370B.

6. Close the Protective Cover.

Table 5-9: Collector Current Accuracy

VERTICAL CURRENT/DIV Calibrator DC Current Vertical CURSOR Readout
Setting
1 A 0.00 A
0.05 A
9.00 A 8.82 Ato9.18 A
20 A 0.00 A
1.0 A
180.00 A 176.3 Ato183.7 A
500 A 0.00 A
25 A
4500 A 4408 Ato4592 A
1 mA 0.00 A
0.05 mA
9.00 mA 8.82 mAto9.18 mA
20 mA 0.00 A
1.0 mA
180.0 mA 176.3 mAto183.7 mA

370B Service Manual 5-63

Performance Verification

E6b. Checking n
COLLECTOR CURRENT
Specification:
Accuracy for 500 mA/DIV
through 2 A/DIV (Alternate H STORE mode COLLECTOR CURRENT/DIV, MAG mode X10 settings are
Method) accurate to within 1.5 % of readout +0.3 division of setting.

NOTE. This step is recommended for full scale measurement of CURRENT/DIV

settings greater than 500 mA/DIV.

DC VoltageSource

To LeftCollector

To LeftEmitter

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
VERTICAL 500 mA COLLECTOR
HORIZONTAL 50 mV COLLECTOR
COLLECTOR SUPPLY
POLARITY + DC
COLLECTOR SUPPLY MAX 400
PEAK VOLTS
CURSOR
Mode DOT
POSITION
Mode DISPLAY
LEFT-RIGHT-STANDBY LEFT
OUTPUT ENABLED
ProtectiveCover Open

5-64 370B Service Manual

 Performance Verification

Test Equipmentsetting
Calibrator
Output 112.5 mV

Checking Accuracy.
1. Move the spot to the graticule center with the Position Control buttons.
2. Change the following 370B setting:

MAG X10 On

3. Note the Horizontal CURSOR readout.

4. Change the following Test equipment and 370B settings:

Calibrator
Output 225 mV
370B
MAG X10 Off
POSITION Move the spotto the graticulecenter
withthe PositionControlbuttons.

5. Change the following 370B setting:

MAG X10 On

6. Note the Horizontal CURSOR readout.

7. Change the following Test equipment and 370B settings:

Calibrator
Output 250 mV
370B
MAG X10 Off
POSITION Move the spotto the graticulecenter
withthe PositionControlbuttons.

8. Change the following 370B setting:

MAG X10 On

370B Service Manual 5-65

Performance Verification

9. Note the Horizontal CURSOR readout.

10. Change the following Test Equipment and 370B settings:

Calibrator
Output Standby
370B
MAG X10 Off
COLLECTOR SUPPLY 16
MAX PEAK VOLTS
MAX PEAK POWER 220
WATTS
POSITION Simultaneouslypressthe up and
downPositionControlbuttons,then
simultaneouslypressthe leftand
rightPositionControlbuttons.

11. Disconnect the Calibrator.

12. Connect the 0.025
resistor as shown in Figure 5-3, then close the
Protective Cover.
13. Change the following 370B setting:

VARIABLECOLLECTOR Clockwiseuntilthe HorizontalCURSOR

SUPPLY readoutto about112.5 mV.

14. Move the spot to the graticule center with the Position Control buttons.
15. Change the following 370B setting:

MAG X10 On
VARIABLECOLLECTOR Set so the HorizontalCURSOR readout
SUPPLY is nearestthatnotedin part3.

Difference value should be within 0.5 mV.

5-66 370B Service Manual

 Performance Verification

To LEFT
COLLECTOR
SENSE

To LEFT
COLLECTOR

To LEFT EMITTER

To LEFT EMITTER SENSE

Figure 5-3: Checking Collector high current range

16. CHECK that the Vertical CURSOR readout is within the limits given in
Table 5-10 for 50 mA/DIV.

Table 5-10: Collector High Current Accuracy

VERTICAL CURRENT/DIV VARIABLE COLLECTOR Vertical CURSOR Readout
Setting SUPPLY
50 mA 112.5 mV (4.5A) 4500
82.5 mA
100 mA 225 mV (9A) 9000
165 mA
200 mA 250 mV (10A) 10000
210 mA

Checking 1 A/DIV Accuracy.

17. Change the following 370B settings:

MAG X10 Off

POSITION Simultaneouslypressthe up and
downPositionControlbuttons,then
simultaneouslypressthe leftand
rightPositionControlbuttons.

370B Service Manual 5-67

Performance Verification

DISPLAY
VERTICAL 1A COLLECTOR
VARIABLECOLLECTOR Clockwiseuntilthe Horizontal
SUPPLY CURSOR readoutto about250 mV.

18. Move the spot to the graticule center with the Position Control buttons.
19. Change the following 370B settings:

MAG X10 On
VARIABLECOLLECTOR Set so the HorizontalCURSOR
SUPPLY readoutis nearestthatnotedin part6.

Difference value should be within 0.5 mV.

20. CHECK that the Vertical CURSOR readout is within the limits given in
Table 5-10 for 100 mA/DIV when the Horizontal CURSOR readout is the
same as that in part 6.

Checking 2 A/DIV Accuracy.

21. Change the following 370B settings:

MAG X10 Off

DISPLAY
VERTICAL 2A COLLECTOR
VARIABLECOLLECTOR Move the spotto the graticulecenter
SUPPLY withthe PositionControlbuttons.

22. Change the following 370B settings:

MAG X10 On
VARIABLECOLLECTOR Set so the HorizontalCURSOR
SUPPLY readoutis nearestthatnotedin part9.

Difference value should be within 0.5 mV.

23. CHECK that the Vertical CURSOR readout is within the limits given in
Table 5-10 for 200 mA/DIV when the Horizontal CURSOR readout is the
same as that in part 6.

5-68 370B Service Manual

 Performance Verification

Removing the Setup.

24. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

25. Open the Protective Cover.

26. Remove the resistor.

E7. Checking Vertical n

Displayed Noise
Specifications:
H Collector and Base Current Mode Vertical Displayed noise are accurate to
within 1 A at 16 V and 80 V, 2 A at 400 V, 5 A at 2000 V MAX PEAK
VOLTS setting, except for switching noise at + and - mode.

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
Mode NON STORE
VERTICAL CURRENT/DIV 1 A COLLECTOR
HORIZONTAL VOLTS/DIV 500V COLLECTOR
COLLECTOR SUPPLY MAX
PEAK VOLTS 2000V
POSITION
Mode DISPLAY
OUTPUTS ENABLED
VARIABLECOLLECTOR 100 %
SUPPLY
ProtectiveCover Closed

370B Service Manual 5-69

Performance Verification

Checking Collector Vertical Displayed Noise In CONFIGURATION COLLECTOR to

COLLECTOR SUPPLY mode.
1. Press the up Position Control button to move the displayed waveform to
center graticule.
2. Set the front-panel LOOPING COMPENSATION to minimum looping.
3. CHECK that vertical width of the displayed waveform is within the limits
5 mA (5 div) at the 100 % of VARIABLE COLLECTOR SUPPLY setting.

Checking Collector Vertical Displayed Noise in CONFIGURATION BASE to COLLEC-

TOR SUPPLY mode.
4. Change the following 370B setting:

CONFIGURATION BASE COLLECTOR

SUPPLY

5. Set the front-panel LOOPING COMPENSATION to minimum looping.

6. CHECK that vertical width of the displayed waveform is within the limits
given in Table 5-11 for each combination of settings for the MAX PEAK
VOLTS and the HORIZONTAL VOLTS/DIV controls with the 100 % of
VARIABLE COLLECTOR SUPPLY setting.

Table 5-11: Displayed Vertical Collector Noise in CONFIGURATION BASE to

COLLECTOR SUPPLY mode
COLLECTOR SUPPLY MAX HORIZONTAL COLLECTOR Vertical width of the
PEAK VOLTS VOLTS/DIV Setting waveform
16 2 V/DIV 1 A (1 div)
80 10 V/DIV 1 A (1 div)
400 50 V/DIV 2 A (2 div)

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 Performance Verification

Step Generator
Equipment Required (see Table 5-3):
H Digital Multimeter
H Resistor, 1 M
, 5 %, 0.5 W
H Resistor, 100
, 5 %, 0.5 W
H Resistor, 0.025
, 0.1 %, 4 W

F1. Adjusting.1X Balance NOTE. The characteristic examined in this step is provided as an example of
(A3R332) and Step typical instrument operation to aid in the adjustment of R332, R360; it is not a
Generator Offset (A3R360) specification.

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
COLLECTOR SUPPLY AC
POLARITY
STEP GENERATOR
Mode VOLTAGE
STEP MULTI .1X On
STEP AMPLITUDE 200 mV
NUMBER OF STEPS 0
MAX X10 On
DISPLAY
HORIZONTAL 5 mV BASE/EMITTER

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Performance Verification

OUTPUTS ENABLED
ProtectiveCover Closed

Examining and Adjusting for Zero Output Volts.

1. Note the horizontal spot position.

2. Change the following 370B setting:

STEP GENERATOR
STEP MULTI .1X Off

3. EXAMINE that the spot moves within
1 divisions from the noted position
of step 1.
If the spot is not within this limit, the following adjustment is necessary.
4. ADJUST .1X Balance adjustment R332 on the A3 A/D board for minimum
horizontal display shift, when STEP MULTI .1X is set between On and Off.

Examining and Adjusting for Step Generator Offset.

5. Set the following Test Equipment setting:

DigitalMultimeterMode DC Volts

6. Connect the Digital Multimeter between the TP310 (SG) and the TP 500
(A GND) on the A3 A/D board as shown in Figure 5-4.

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 Performance Verification

To A3TP310

DigitalMultimeter

To A3TP500

Figure 5-4: Examining and Adjusting for Step Generator Offset

7. EXAMINE the Digital Multimeter for reading of 0 mV,
1 mV.

If the Digital Multimeter reading is not within this limit, the following adjust-
ment is necessary.
8. ADJUST the Step Generator Offset adjustment R360 on the A3 A/D board
for 0 mV of Digital Multimeter reading.

Removing the Setup.

9. Disconnect the Digital Multimeter from 370B.

370B Service Manual 5-73

Performance Verification

F2. Adjusting Step {

Generator Zero (A7R310)
Current Amplifier Bias NOTE. The characteristic examined in this step is provided as an example of
(A7R467) Current Zero typical instrument operation to aid in the adjustment of R310, R467, R603; it is
(A7R6O3) not a specification.

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
COLLECTOR SUPPLY AC
POLARITY
STEP GENERATOR
VOLTAGE On
STEP AMPLITUDE 500 mV
NUMBER OF STEPS 0
MAX X10 On
DISPLAY
Mode NON STORE
HORIZONTAL 5 mV BASE/EMITTER
OUTPUTS ENABLED
ProtectiveCover Closed

Examining and Adjusting for Zero Output Volts.

1. EXAMINE that the spot moves within
0.5 divisions, between the 500 mV
and 200 mV of STEP AMPLITUDE setting.
If the spot is not within this limit, the following adjustment is necessary.

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 Performance Verification

2. Set the STEP AMPLITUDE to 200 mV, then note the spot position.
3. Set the STEP AMPLITUDE to 500 mV.
4. ADJUST SG ZERO adjustment R310 on the A7 Step Generator Board to the
noted position of part 2.

Adjusting for Current Amplifier Bias.

5. Set the following 370B and Test Equipment settings:

STEP GENERATOR
Mode CURRENT
DigitalMultimeterMode DC Volts

6. Connect the Digital Multimeter across R491 on the A7 Step Generator Board
as shown in Figure 5-5.

DigitalMultimeter

MeasureacrossA7R491

Figure 5-5: Adjusting for Current Amplifier Bias

7. ADJUST BIAS adjustment R467 on the A7 Step Generator Board for a

Digital Multimeter reading of 6 mV.
This adjustment sets bias current to the optimum level for long term reliability.

Removing the Setup.

8. Disconnect the Digital Multimeter from R491.

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Performance Verification

Checking and Adjusting for Zero Output Current.

9. Connect the 100
resistor to the Left Base and Left Emitter jacks, then
close the protective cover.
10. Change the following 370B settings:

DISPLAY
HORIZONTAL 100 mV BASE/EMITTER
STEP GENERATOR
STEP AMPLITUDE 100 mA
LEFT-RIGHT-STANDBY LEFT

11. Note the horizontal position of the spot.

12. Change the following 370B settings:

DISPLAY
HORIZONTAL 50 mV BASE/EMITTER
STEP GENERATOR
STEP AMPLITUDE 50 mA

13. EXAMINE that the spot moves within
0.5 divisions, between the setting
of part 10 and 12.
If the spot is not within this limit, the following adjustment is necessary.
14. ADJUST Current Zero adjustment R603 on the A7 Step Generator Board to
move the spot one-half over the noted position of part 11.
15. If necessary, repeat steps 10 through 14.

Removing the Setup.

16. Remove the 100
resistor.

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 Performance Verification

F3. Adjusting Current {

Balance (A7R325)
NOTE. The characteristics examined in this step is provided as an example of
typical instrument operation to aid in the adjustment of R325; it is not a
specification.

To LeftBase

PatchCord

To LeftEmitter

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
COLLECTOR SUPPLY 220
MAX PEAL POWER WATTS
STEP GENERATOR
STEP AMPLITUDE 10 mV
NUMBER OF STEPS 0
PULSE LONG
DISPLAY
VERTICAL CURRENT 1 mA COLLECTOR
CURSOR DOT
POSITION DISPLAY
OUTPUTS ENABLED
LEFT-RIGHT-STANDBY LEFT
ProtectiveCover Closed

370B Service Manual 5-77

Performance Verification

Examining for Current Balance.

1. Move the spot to vertical graticule center while pressing the “up” Position
Control button.
2. Note the vertical CURSOR readout.
3. Turn the VARIABLE COLLECTOR SUPPLY for a horizontal cursor
readout of 10.00 V.
4. EXAMINE the vertical CURSOR readout for the difference in value from
part 3 is between 0.00 and 0.30 mA.
If it is not within this limit, the following adjustment is necessary.

Adjusting for Current Balance.

5. Adjust R325 on A7 Step Generator board to the value noted in part 3.

Removing the Setup.

6. Remove the patch cord.

F4. Checking OFFSET n

Accuracy in VOLTAGE
Specification:
Mode
H Absolute accuracy is less than (1.5 % of the total output + 3 % of the STEP
AMPLITUDE setting + 1 mV).

DigitalMultimeter

To LeftBase

To LeftEmitter

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.

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 Performance Verification

DISPLAY
HORIZONTAL 5 V BASE/EMITTER
STEP GENERATOR
Mode Voltage
STEP AMPLITUDE 2V
OFFSET 0.0 mV
NUMBER OF STEPS 0
COLLECTOR SUPPLY AC
POLARITY
LEFT-RIGHT-STANDBY LEFT
OUTPUTS ENABLED
ProtectiveCover Closed
Test EquipmentSettings:
DigitalMultimeterMode DC Voltage

Checking Zero OFFSET without INVERT.

1. CHECK that it is within the range of 0.0
61mV that digital multimeter
measurement is limit value.

Checking Maximum OFFSET without INVERT.

2. Change the following 370B setting:

STEP GENERATOR
STEP AMPLITUDE 200 mV
OFFSET AID -2 V

3. CHECK that the digital multimeter measurement is within the limits shown
in Table 5-12 under Maximum OFFSET for each setting of the STEP
AMPLITUDE control.

Table 5-12: OFFSET Voltage

STEP AMPLITUDE Digital Multimeter Reading
(Max OFFSET)
200 mV + 1963 mV to + 2037 mV
2V + 19.64 V to + 20.36 V

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Performance Verification

Checking Maximum OFFSET with INVERT.

4. Change the following 370B settings:

STEP GENERATOR
POLARITY INVERT ON (*)

(*) The indicator above the INVERT button will light up.

5. CHECK that the Digital Multimeter measurement is within the limits shown
in Table 5-13 under Maximum OFFSET for each setting of the STEP
AMPLITUDE control.

Table 5-13: OFFSET Voltage

STEP AMPLITUDE Digital Multimeter Reading
(Max OFFSET)
100 mV - 1019 mV to - 981 mV
1V - 10.18 V to - 9.82 V

Removing the Setup.

6. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

7. Remove the digital multimeter leads from the 370B.

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 Performance Verification

F5. Checking OFFSET n {

Accuracy in CURRENT
Specifications:
Mode
H Absolute Accuracy is less than (1.5 % of the total output + 3 % of the STEP
AMPLITUDE setting + 1 nA).

DigitalMultimeter

To LeftBase

To LeftEmitter

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
HORIZONTAL CURRENT STEP GEN
STEP GENERATOR
Mode CURRENT
STEP AMPLITUDE 200 nA
OFFSET AID - 2000 nA
NUMBER OF STEPS 0
POLARITY INVERT ON
OUTPUTS ENABLED
ProtectiveCover Closed
Test EquipmentSettings: -2
DigitalMultimeterMode DC Current

NOTE. Before checking these parameters, note the count error of the Digital
Multimeter and subtract it from the reading obtained in the procedure.
Use a TEKTRONIX DM501A for measuring the 200 mA range.

370B Service Manual 5-81

Performance Verification

Checking Maximum OFFSET with INVERT.

1. CHECK that the Digital Multimeter measurement is within the limits shown
in Table 5-14 under Maximum OFFSET for each setting of the STEP
AMPLITUDE control.

Table 5-14: OFFSET Current

STEP AMPLITUDE Digital Multimeter Reading Limits with
Setting (
) max OFFSET (
)
200nA
1963mA to
2037 mA
2 A
19.64 A to
20.36 A
20 A
196.4 A to
203.6 A
200 A
1964 A to
2036 A
2 mA
19.64 mA to
20.36 mA
20 mA
196.4 mA to
203.6 mA
200 mA
1964 mA to
2037 mA

Checking Maximum OFFSET without INVERT.

2. Change the following 370B setting:

STEP GENERATOR
POLARITY INVERT Off

The INVERT indicator will go out.

3. CHECK that the digital multimeter measurement is within the limits shown
in Table 5-14 under Maximum OFFSET for each setting of the STEP
AMPLITUDE control.

Removing the Setup.

4. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

5. Remove the Digital Multimeter.

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 Performance Verification

Alternate Method.
6. Change the following Test Equipment setting:

DigitalMultimeterMode Volts
7. Connect a 0.025
Resistor to the Left Base jack (B) to the Left Emitter jack
(E) and connect the Digital Multimeter to the leads of the Resistor as shown
in Figure 5-6.

DigitalMultimeter
To LeftBase

25 m
To LeftEmitter
0.1 %, 4 W
Resistor

Figure 5-6: Checking for Maximum OFFSET of 200 mA Range

Checking Maximum OFFSET of 200 mA Range.

8. Change the following 370B settings:

STEP GENERATOR
POLARITY INVERT Off
STEP AMPLITUDE 200 mA
OFFSET 2000 mA

9. CHECK that the Digital Multimeter readout is 49.1 mV to 50.9 mV.

10. Change the following 370B settings:

STEP GENERATOR
POLARITY INVERT ON

11. CHECK that the Digital Multimeter readout is -49.1 mV to -50.9 mV.

370B Service Manual 5-83

Performance Verification

12. Removing the Setup.

13. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

14. Remove the Digital Multimeter.

F6. Checking Step n

Incremental Accuracy in
Specifications :
VOLTAGE Mode
H Incremental accuracy is 1.5 %.

DigitalMultimeter

To LeftBase

To LeftEmitter

370B settings:
Initializethe 370B; thenset the followingcontrolsas indicated.
DISPLAY
Mode NON STORE
HORIZONTAL VOLTS 2 V BASE/EMITTER
COLLECTOR SUPPLY +DC
POLARITY
STEP GENERATOR
Mode VOLTAGE
STEP AMPLITUDE 2V
NUMBER OF STEPS 10
POSITION DISPLAY
LEFT-RIGHT-STANDBY LEFT
OUTPUTS ENABLED
ProtectiveCover Closed

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 Performance Verification

Test EquipmentSettings:
DigitalMultimeterMode DC Voltage

NOTE. See Test poit and Adjustment Location 1 for the locatin of the circuit
board and jumper associated with this step

Moving the Store/Non-Store Jumper.

1. Change the following 370B setting:

POWER OFF

2. Remove the A3 A/D Board from the card cage located on the right side of
the 370B.

NOTE. See test Point and Adjiustment Locations 1 for the location of A3 and
jumper J34. For details on removing and replacing Plug-in Bords, see the
instructions under “Component Removal and Replacement” in section 3,
maintenance.

3. Change the position of Jumper J34 from pins 1 - 2 to pins 2 - 4 (CAL

position).
When the jumper is moved from pins 1 - 2 to pins 2 - 4, STORE Mode is
disabled.
4. Replace the A3 A/D Board in the 370B card cage. Do not re-install the
circuit board retainers.
5. Change the following 370B setting:

POWER ON

6. Press the up and right Position Control buttons to moved the displayed spot
to the graticule center (V:5.0 H:5.0).

Checking Step 0 and 1.

7. Record the value of the digital multimeter reading.
8. Change the following 370B setting:

370B Service Manual 5-85

Performance Verification

MEASUREMENT Pressthe MESUREMENT REPEAT buttonto movethe

displayedspot1 divisionto the right.

9. Record the value of the digital multimeter reading.

10. CHECK the reading value for Step 1 differs from the reading value for Step0
within 2.000V
30 mV.

Checking Steps 2 through 10.

11. CHECK that for each time the spot is advanced 1 division with the
MEASUREMENT REPEAT button.
12. Record the value of the digital multimeter reading.
13. CHECK the voltage difference from the previous value are within
2.000 V
30 mV.

Checking INVERT.
14. Change the following 370B setting:

STEP GENERATOR
POLARITY INVERT On

Step Generator output should be automatically return to Step 0.

15. Record the value of the digital multimeter reading and CHECK the voltage
difference for INVERT by repeating parts 7 through 13 (For INVERT, the
spot will move in the opposite direction).

NOTE. If steps F7., F8., F9. and F10. will not be performed, complete the
instructions given under Replacing the Store/Non-Store Jumper, at the end of
Step F13, before proceeding to another step or ending the procedure.

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 Performance Verification

F7. Checking Step Multi .1X n

Accuracy in VOLTAGE Mode
Specification:
H Incremental accuracy is 1.5 %.

NOTE. If the previous step was not performed, complete the instructions given
under Moving the Store/Non-Store Jumper, at the beginning of Step F8, before
proceed ing with this step.

DigitalMultimeter

To LeftBase

To LeftEmitter

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
Mode NON STORE
HORIZONTAL VOLTS 2 V BASE/EMITTER
COLLECTOR SUPPLY +DC
POLARITY
STEP GENERATOR
Mode VOLTAGE
STEP AMPLITUDE 2V
NUMBER OF STEPS 10
POSITION DISPLAY
LEFT-RIGHT-STANDBY LEFT
OUTPUTS ENABLED
ProtectiveCover Closed
Test EquipmentSettings:

370B Service Manual 5-87

Performance Verification

DigitalMultimeterMode DC Voltage
pressthe up and rightPositionControlbuttonsto movethe
displayedspotto the graticulecenter(V:5.0 H:5.0).

Checking Step 0 and 1.

1. Change the following 370B settings:

STEP GENERATOR
STEP MULTI .1X On
MAG X10 On

2. Record the value of the digital multimeter reading.

3. Change the following 370B setting:

MEASUREMENT Pressthe REPEAT buttonto move

the spot1 divisionto the right.

4. Record the value of the digital multimeter reading.

5. CHECK the reading value for Step 1 differs from the reading value for Step0
within 200 mV
3 mV.

Checking Steps 2 through 10.

6. CHECK that for each time the spot is advanced 1 division with the
MEASUREMENT REPEAT button.
7. Record the value of the digital multimeter reading.
8. CHECK the voltage difference from the previous reading are within
200 mV
3 mV.

NOTE. If steps F8, F9, and F10. will not be performed, complete the instructions
given under Replacing the Store/Non-Store Jumper, at the end of Step F10,
before proceeding to another step or ending the procedure.

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 Performance Verification

F8. Checking Step n

Incremental Accuracy in
Specifications:
CURRENT Mode
H Incremental Accuracy is 1.5 %.

NOTE. If previous step was not performed, complete the instruction given under
Moving the Store/Non-Store Jumper, at the beginning of Step F6, before
proceeding with this step.

DigitalMultimeter

To LeftBase

To LeftEmitter

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
Mode NON STORE
VERTICAL CURRENT STEP GEN
COLLECTOR SUPPLY +DC
POLARITY
STEP GENERATOR
Mode CURRENT
STEP AMPLITUDE 200 mA
NUMBER OF STEPS 10
LEFT-RIGHT-STANDBY LEFT
OUTPUTS ENABLED
ProtectiveCover Closed
Test EquipmentSettings:
DigitalMultimeterMode DC Current

370B Service Manual 5-89

Performance Verification

Checking Accuracy of Steps 0 and 1.

1. Record the value of digital multimeter reading.
2. press MEASUREMENT REPEAT once.
Note that the displayed spot moves 1 division higher.
3. CHECK the reading value for Step 1 differs from the reading value for Step0
within 200 mA
3 mA.

Checking Accuracy of Steps 2 through 10.

4. CHECK that for each time the spot is advanced 1 division with the
MEASUREMENT REPEAT button.
5. Record the value of the digital multimeter reading.
6. CHECK the current difference from the previous reading are within
200 mA
3 mA.

NOTE. If step, F9. and F10. will not be performed, complete the instructions
given under Replacing the Store/ Non-Store Jumper, at the end of Step F10
before proceeding to another step or ending the procedure.

Removing the Setup.

7. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

8. Remove the Digital Multimeter.

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 Performance Verification

F9. Checking Maximum n

Voltage Output in
Specifications :
VOLTAGE Mode
H Absolute accuracy of the Step Generator is less than 1.5 % of the output
voltage +3 % of the STEP AMPLITUDE setting + 1 mV.
H Maximum voltage output is 20 times the STEP AMPLITUDE setting.

NOTE. If previous step was not performed, complete the instructions given under
Moving the Store/Non-Store Jumper, at the beginning of Step F8, before
proceeding with this step.

DigitalMultimeter

To LeftBase

To LeftEmitter

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
Mode NON STORE
HORIZONTAL VOLTS/DIV STEP GEN
COLLECTOR SUPPLY +DC
POLARITY
STEP GENERATOR
Mode VOLTAGE
STEP AMPLITUDE 2V
NUMBER OF STEPS 10
OFFSET 20 V
POSITION DISPLAY
LEFT-RIGHT-STANDBY LEFT

370B Service Manual 5-91

Performance Verification

OUTPUTS ENABLED
ProtectiveCover Closed
Test EquipmentSettings:
DigitalMultimeterMode DC Voltage

Checking Maximum Voltage.

1. Simultaneously press the FAST/SHIFT and left Position Control buttons to
move the displayed spot to the left-most graticule line.
2. Change the following 370B setting:

MEASUREMENT Pressthe REPEAT buttonseveral

timesto movethe displayedspotto
the right-mostgraticuleline.

The Digital Multimeter reading should be approximately 40 V.

3. Check that the digital multimeter reading is between 39.34 and 40.66 V

Checking INVERT.
4. Press the STEP GENERATOR INVERT button to On.
Step Generator output should be automatically return to Step 0.
5. Simultaneously press the FAST/SHIFT and right Position Control buttons
to move the displayed spot to the right-most graticule line.
6. Change the following 370B settings:

MEASUREMENT Pressthe REPEAT buttonseveral

timesto movethe displayedspotto
the left-mostgraticuleline.

The Digital Multimeter reading should be approximately -40 V.

7. Check that the digital multimeter reading is between -40.66 V and -39.34 V

Removing the Setup.

8. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

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 Performance Verification

9. Remove the Digital Multimeter.

NOTE. If step F10 will not be performed, complete the instructions given under
Replacing the Store/Non-Store Jumper, at the end of Step F10, before proceeding
to another step or ending the procedure.

F10. Checking Maximum n

Current Output in
Specification:
CURRENT Mode
H Absolute Accuracy is less than (1.5 % of the total output + 3 % of the STEP
AMPLITUDE setting + 1 nA).
H Maximum current output is 20 times the STEP AMPLITUDE setting, except
at 200 mA, where it is 10 times the setting.

NOTE. If the previous step was not performed, complete the instructions given
under Moving the Store/Non-Store Jumper, at the beginning of Step F8, before
proceeding with this step.

DigitalMultimeter

To LeftBase

To LeftEmitter

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
Mode NON STORE
HORIZONTAL VOLTS/DIV STEP GEN

370B Service Manual 5-93

Performance Verification

COLLECTOR SUPPLY +DC

POLARITY
STEP GENERATOR
Mode CURRENT
STEP AMPLITUDE 100 mA
NUMBER OF STEPS 10
OFFSET 500 nA
POSITION DISPLAY
LEFT-RIGHT-STANDBY LEFT
OUTPUTS ENABLED
ProtectiveCover Closed
Test EquipmentSettings:
DigitalMultimeterMode DC Current

NOTE. Before checking these parameters, note the count error of the Digital
Multimeter and subtract it from the reading obtained in the procedure.

Checking about 100 mA.

1. Simultaneously press the FAST/SHIFT and left Position Control buttons to
move the displayed spot to the left-most graticule line.
2. Change the following 370B setting:

MEASUREMENT Pressthe REPEAT button

severaltimesto movethe
displayedspotto the right-
mostgraticuleline.

The Digital Multimeter reading should be approximately 2000 mA.

3. Check that the digital multimeter reading is between 1967 mA and 2033 mA

NOTE. Use a TEKTRONIX DM501A to check.

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 Performance Verification

Checking INVERT.
4. Press the STEP GENERATOR INVERT button to On.
Step Generator output should be automatically return to Step 0.
5. Simultaneously press the FAST/SHIFT and right Position Control buttons
to move the displayed spot to the right-most graticule line.
6. Change the following 370B settings:

MEASUREMENT Pressthe REPEAT buttonseveraltimesto movethe displayed

spotto the left-mostgraticuleline.

The Digital Multimeter reading should be approximately -2000 mA.

7. Check that the digital multimeter reading is between -1967 and -2033 mA

Removing the Setup.

8. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

9. Disconnect the digital multimeter leads from the 370B.

Alternate Method.
10. Change the following 370B and Test Equipment settings:

STEP GENERATOR Off

POLARITY INVERT
STEP AMPLITUDE 100 mA
DigitalMultimeterMode Volts

11. Connect a 0.025
Resistor between the Left Base jack (B) and the Left
Emitter jack (E) and connect the Digital Multimeter to the leads of the
Resistor as shown in Figure 5-7.

370B Service Manual 5-95

Performance Verification

DigitalMultimeter
To LeftBase

25 m
To LeftEmitter
0.1 %, 4 W
Resistor

Figure 5-7: Checking for Maximum Current Output of 100 mA and 200 mA range

Checking 100 mA.

12. Simultaneously press the FAST/SHIFT and left Position Control buttons to
move the displayed spot to the left-most graticule line.Change the following
370B settings:

LEFT-RIGHT-STANDBY LEFT
ProtectiveCover Closed
MEASUREMENT Pressthe REPEAT buttonseveral
timesto movethe displayedspotto
the right-mostgraticuleline.

13. CHECK that the Digital Multimeter readout is 49.175 mV to 50.825 mV.

Checking -100 mA.

14. Change the following 370B settings:

STEP GENERATOR On
POLARITY INVERT
STEP AMPLITUDE 100 mA

15. Simultaneously press the FAST/SHIFT and right Position Control buttons
to move the displayed spot to the right-most graticule line.
16. CHECK that the Digital Multimeter readout is -50.825 mV to -49.175 mV.

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 Performance Verification

Removing the Setup.

17. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

18. Remove the resistor and the Digital Multimeter.

NOTE. Maximum 370B Step Generetor current is 2 A; therefore, the 100 mA

STEP GENERATOR STEP AMPLITUDE settimg have the same performance
requirement.

Replacing the Store/Non-Store Jumper.

19. Change the following 370B setting:

POWER OFF

20. Remove the A3 A/D Board.

21. Move jumper J34 from pins 2 - 4 to pins 1 - 2 (ZERO position).
22. Replace the A3 A/D Board and the circuit board retainers across the top of
the card cage.
23. Change the following 370B setting:

POWER ON

370B Service Manual 5-97

Performance Verification

F11. Checking Maximum n

Opposing Offset Current
Specification:
in VOLTAGE Mode
H Maximum opposing offset current is less than 20 mA.

To LeftCollector

PatchCord

To LeftBase

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
VERTICAL CURRENT/DIV 5 mA COLLECTOR
COLLECTOR SUPPLY AC
POLARITY
MAX PEAK POWER WATTS 220
STEP GENERATOR
Mode VOLTAGE
STEP AMPLITUDE 2V
NUMBER OF STEPS 0
OFFSET -20 V
CURSOR DOT

Checking without INVERT.

1. Set the LEFT-RIGHT-STANDBY switch to LEFT.
2. CHECK for vertical CURSOR reading of less than 20 mA.

Removing the Setup.

3. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

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 Performance Verification

4. Disconnect the Patch Cord from the 370B.

F12. Checking Maximum n

Opposing Offset Volts in
Specification:
CURRENT Mode
H Maximum Opposing Volts in Current Mode is less than 15 volts.

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
HORIZONTAL VOLTS/DIV 2 V BASE/EMITTER
COLLECTOR SUPPLY AC
POLARITY
STEP GENERATOR
Mode CURRENT
STEP AMPLITUDE 200 mA
NUMBER OF STEPS 0
OFFSET -2000 mA
CURSOR DOT
OUTPUTS ENABLED
ProtectiveCover Closed

Checking Maximum Opposing Volts without INVERT.

1. Set the LEFT-RIGHT-STANDBY switch to LEFT.
2. CHECK that the horizontal CURSOR readout is no more than -15 V.

370B Service Manual 5-99

Performance Verification

Checking Maximum Opposing Volts with INVERT.

3. Change the following 370B setting:

STEP GENERATOR On
POLARITY INVERT

The indicator beside the INVERT button will light.

4. CHECK that the horizontal CURSOR readout is no more than +15 V

F13. Checking PULSE n

Width
Specification
H Pulse Width is 80 s
10 % for the SHORT setting of the PULSE selector
and 300 s
10 % for the LONG setting at half amplitude.

Test Oscilloscope

GND
VerticalInput
To STEP GEN OUT

To 370B GroundJack

370B settings:
Initializethe 370B; thenset the followingcontrolas
indicated.
STEP GENERATOR
Mode VOLTAGE
STEP AMPLITUDE 2V
NUMBER OF STEPS 1
PULSE LONG
OUTPUTS ENABLED
ProtectiveCover Closed
Test Equipmentsettings:

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 Performance Verification

Test Oscilloscope
VerticalSensitivity 500 mV/divDC
Horizontal 50 s/div
TriggerMode Auto
TriggerSlope +

Checking LONG PULSE Width.

1. CHECK that the pulse width is 300 s
10 % (as measured by the test
oscilloscope).

Checking SHORT PULSE Width.

2. Change the following 370B and Test Equipment settings:

370B:
STEP GENERATOR SHORT
PULSE
Test Equipmentsettings:
Test Oscilloscope
Horizontal 10 s/div

3. CHECK that the pulse width is 80 s
10 %.

370B Service Manual 5-101

Performance Verification

F14. Examining Step NOTE. The characteristics examined in this step are examples of typical
Generator Polarity instrument operation; they are not specifications.
Operation

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
HORIZONTAL VOLTS/DIV 500 mV BASE/EMITTER
COLLECTOR SUPPLY AC
POLARITY
STEP GENERATOR
Mode VOLTAGE
STEP AMPLITUDE 100 mV
OFFSET 1000 mV
CURSOR DOT
OUTPUTS ENABLED
ProtectiveCover Closed

Examining POLARITY INVERT Operation.

1. Press the POLARITY INVERT button.
2. EXAMINE that the red INVERT LED for lights and the green LED in the
STEP GENERATOR POLARITY window changes from + to -, and the
CRT to see that the displayed waveform changes from right to left from
graticule center.
3. Press the POLARITY INVERT button to OFF.

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 Performance Verification

Examining the CONFIGURATION BASE COMMON Operation.

4. Change the following 370B setting:

CONFIGURATION EMITTER STEP GEN

5. EXAMINE the green LED in the STEP GENERATOR POLARITY window

changes from + to -, and the CRT to see that the displayed waveform
changes from right to left from graticule center.
The red INVERT LED will not light.
6. Change the following 370B setting:

CONFIGURATION BASE STEP GEN

Examining the COLLECTOR SUPPLY POLARITY Operation.

7. Change the following 370B setting:

COLLECTOR SUPPLY -
POLARITY

8. EXAMINE the green LED in the STEP GENERATOR POLARITY window

changes from + to -, and the CRT to see that the displayed waveform is
above the horizontal center graticule line.
The red INVERT LED will not light.

370B Service Manual 5-103

Performance Verification

Collector Supply
Equipment Required (see Table 5-3):
H Digital Multimeter

G1. Adjusting Collector {

Supply Amplifier Offset
(A6R412) NOTE. The characteristics examined in this step are examples of typical
instrument operation; they are not specifications.

370B settings:
POWER OFF

Removing the Electrical Shield.

1. Change the following 370B setting:

POWER OFF

WARNING. To avoid electric shock hazard, be certain the 370B POWER switch is
set to OFF before removing or replacing the electrical shield and connecting the
digital multimeter to the 370B.

2. Use a #1 Pozidrive screwdriver to remove the electric shield on the left side
of the 370B that covers the A6 Collector Supply Board. (These are three
shield on the left side; remove the rear shield.

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 Performance Verification

Adjusting Collector Supply Offset.

3. Change the following Test Equipment setting:

DigitalMultimeterMode DC Voltage

4. Connect the Digital Multimeter test leads to pin 1 and pin 3 of P62 as shown
in Figure 5-8. (These are the COLLECT-OUT and ground pins.)

DigitalMultimeter

To A6P62

Figure 5-8: Adjusting for Collector Supply Amplifier Offset

5. Change the following 370B setting:

POWER ON

6. ADJUST CS OFFSET adjustment R412 on the A6 Collector Supply Board

for a digital multimeter readout of 0.0 mV
0.1 mV.

Removing the Setup.

7. Change the following 370B setting:

POWER OFF

8. Remove the digital multimeter test leads from the 370B.

9. Replace the electrical shield.
10. Change the following 370B setting:

POWER ON

370B Service Manual 5-105

Performance Verification

G2. Checking MAX PEAK { n

VOLTS Accuracy
Specification:
Adjusting Collector
Supply Gain (A6R401 ) H MAX PEAK VOLTS selection include 16, 80, 400, and 2000.
H MAX PEAK VOLTS accuracy for the COLLECTOR SUPPLY is +15 % and
-0 % for 16, 80, 400, and 2000 V settings.

370B settings:
Initializethe 370B; thenset the followingcontrolas
indicated.
COLLECTOR SUPPLY
MAX PEAK POWER 220
WATTS
POLARITY + DC
CURSOR Mode DOT
OUTPUTS ENABLED
VARIABLECOLLECTOR 100 %
SUPPLY
ProtectiveCover Closed

Checking 16 Max Peak Volts.

1. CHECK the horizontal CURSOR readout for a reading within the limits
given in Table 5-15 for 16 MAX PEAK VOLTS.

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 Performance Verification

Checking 80, 400, 2000 MAX PEAK VOLTS.

2. Change the following 370B settings:

DISPLAY
HORIZONTAL VOLTS/DIV 10 V COLLECTOR
COLLECTOR SUPPLY
MAX PEAK POWER 80
WATTS
VARIABLECOLLECTOR 100 %
SUPPLY

3. CHECK the horizontal CURSOR readout for a reading within the limits
given in Table 5-15 for 80 MAX PEAK VOLTS.
4. CHECK that the horizontal CURSOR readout is accurate within the limits
given in Table 5-15 by repeating steps 2 and 3 for each HORIZONTAL
VOLTS/DIV and MAX PEAK VOLTS setting in Table 5-15.
MAX PEAK POWER WATTS should automatically change to 50 when the
MAX PEAK VOLTS setting is changed from 400 to 2000.
If not within these limits, the following adjustment is necessary.

Adjusting Collector Supply Gain.

5. Change the following 370B settings:

370B settings:
DISPLAY
HORIZONTAL VOLTS/DIV 2 V COLLECTOR
COLLECTOR SUPPLY
MAX PEAK POWER 16
VOLTS
MAX PEAK POWER 220 WATTS
WATTS
CURSOR Mode DOT
VARIABLECOLLECTOR 100 %
SUPPLY

6. ADJUST CS Gain adjustment R401 on the A6 Collector Supply Board for a

horizontal CURSOR readout of 17.2 V.
R401 can be adjusted through the access hole in the protective shield.
7. Recheck from 1 to 4.

370B Service Manual 5-107

Performance Verification

Table 5-15: Max Peak Volts

MAX PEAK VOLTS HORIZONTAL MAX PEAK POWER Horizontal CURSOR
VOLTS/DIV setting WATTS setting Readout Limits
setting
16 2V 220 16.0 V to 18.4 V
80 10 V 220 80.0 V to 92.0 V
400 50 V 220 400 V to 460 V
2000 500 V 50 2000 V to 2300 V

G3. Checking DC Mode n

Ripple
H DC Mode Ripple tor 2 % of the full range voltage.

370B settings:
Initializethe 370B; thenset the followingcontrolas
indicated.
DISPLAY Mode NON STORE
COLLECTOR SUPPLY
MAX PEAK POWER 220
WATTS
POLARITY + DC
POSITION DISPLAY
OUTPUTS ENABLED
VARIABLECOLLECTOR 100 %
SUPPLY
ProtectiveCover Closed

Checking 16 MAX PEAK VOLTS DC Mode Ripple.

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 Performance Verification

1. Move the spot to graticule center with the Position Control buttons.
2. Change the following 370B setting:

MAG X10 On

3. CHECK the display spot for its width to be within the limit given in Table
5-16 for 16 MAX PEAK VOLTS.

Checking 2000 MAX PEAK VOLTS DC Mode Ripple.

4. Change the following 370B settings:

DISPLAY
HORIZONTAL VOLTS / DIV 50 V COLLECTOR
COLLECTOR SUPPLY
MAX PEAK VOLTS 2000
VARIABLE 100 %
COLLECTORSUPPLY

5. Move the spot to graticule center with the right Position Control button.
6. CHECK the display spot for its width to be with the limit given in
Table 5-16 for 2000 MAX PEAK VOLTS.
MAX PEAK POWER WATTS should be automatically change to 50 when the
MAX PEAK VOLTS setting is changed from 16 to 2000.

Table 5-16: Max Peak Volts

MAX PEAK VOLTS HORIZONTAL MAX PEAK POWER Maximum Spot
setting VOLTS/DIV setting WATTS Width (Ripple)
16 200 mV 220 320 mV (1.6 div)
2000 50 V 50 40 V (0.8 div)

G4. Checking Maximum n

Peak Currents
Specification:
H Minimum Current Available Current is ≥10 A for the 16 V COLLECTOR
SUPPLY, ≥2 A for 80 V, 400 mA for 400 V, and 50 mA for 2000 V.

370B Service Manual 5-109

Performance Verification

PATCH CORD

370B settings:
Initializethe 370B; thenset the followingcontrolas
indicated.
DISPLAY
HORIZONTAL VOLT/DIV 500
COLLECTOR SUPPLY
MAX PEAK POWER 220
WATTS
POLARITY + DC
CURSOR Mode DOT
POSITION DISPLAY
OUTPUTS ENABLED
LEFT-RIGHT-STANDBY RIGHT
ProtectiveCover Closed

Checking 16 V Maximum Current.

1. CHECK that the trace can reach the value specified in Table 5-17 when
VARIABLE COLLECTOR SUPPLY control is turned clockwise.

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 Performance Verification

Checking 80, 400, 2000 V Maximum Current.

2. Change the following 370B settings:

DISPLAY
VERTICAL CURRENT/DIV 500 mA
COLLECTOR SUPPLY
MAX PEAK VOLTS 80

3. CHECK that the trace can reach the value specified in Table 5-17 when
VARIABLE COLLECTOR SUPPLY control is turned clockwise.
4. CHECK that the trace can reach the value specified in Table 5-17 by
repeating steps 2 and 3 for each VERTICAL CURRENT/DIV and MAX
PEAK VOLTS setting in Table 5-17.
MAX PEAK POWER WATTS should be automatically change to 50 when the
MAX PEAK VOLTS setting is changed from 400 to 2000.

Removing the Setup.

5. Change the following 370B settings:

COLLECTOR SUPPLY
MAX PEAK VOLTS 16 V
LEFT-RIGHT-STANDBY STANDBY

6. Remove the patch cord from the 370B.

Table 5-17: Maximum Peak Currents

MAX PEAK VOLTS MAX PEAK POWER VERTICAL CUR- VERTICAL
settings WATTS RENT/DIV setting CURSOR Readout
16 V 220 W 2A 10 A (5 div)
80 V 220 W 500 mA 2 A (4 div)
400 V 220 W 100 mA 400 mA (4 div)
2000 V 50 W 10 mA 50 mA (5 div)

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Performance Verification

G5. Examining the NOTE. The characteristics examined in this step are examples of typical
Interlock system and instrument operation; they are not specifications.
POLARITY Settings

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
Mode NON STORE
OUTPUTS ENABLED
LEFT-RIGHT-STANDBY LEFT
ProtectiveCover Closed

Examining Collector Supply Variable Operation and + POLARITY.

1. EXAMINE the display, as the VARIABLE COLLECTOR SUPPLY control
is rotated clockwise, for the trace to become a horizontal line starting in the
lower left corner and extending continuously to right along the bottom
horizontal graticule.

Examining Interlock system and Warning LED.

2. EXAMINE that the red LED beside the WARNING lettering is lit.
3. Open the Protective Cover.
4. EXAMINE that the red LED display turns off and that the displayed trace is
go back to lower left corner.

Examining OUTPUTS Operation.

5. Close the Protective Cover.

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 Performance Verification

6. EXAMINE the displayed spot extends toward 100 % as the VARIABLE

COLLECTOR SUPPLY control is rotated clockwise.
7. Set the OUTPUTS to DISABLED.
8. EXAMINE that the displayed trace goes back to lower left corner and that
the OUTPUT DISABLED message appears for a few seconds in the lower
left corner of the display.
9. Set the OUTPUTS to ENABLED.
10. EXAMINE that the OUTPUT ENABLED message appears in the the lower
left corner of the display for a few seconds.

Examining +DC POLARITY.

11. Change the following 370B and Test Equipment settings:

370B:
COLLECTOR SUPPLY + DC
POLARITY
VARIABLECOLLECTOR 100 %
SUPPLY
Test Oscilloscope:
Vertical 5 V/divDC
TriggerMode auto

12. Connect the Test Oscilloscope as shown in Figure 5-9 and close the
Protective Cover.

Test Oscilloscope

GND
VerticalInput
To LeftCollector

To 370B GroundJack

Figure 5-9: Examining for DC and LEAKAGE operation

370B Service Manual 5-113

Performance Verification

13. EXAMINE the display for the spot to move from the lower left corner along
the bottom horizontal graticule line as the VARIABLE COLLECTOR
SUPPLY control is rotated clockwise to 100 %.
14. EXAMINE the Test Oscilloscope display for DC.

Examining +LEAKAGE POLARITY.

15. Change the following 370B setting:

COLLECTOR SUPPLY + LEAKAGE

POLARITY

16. EXAMINE the display for the spot to position the same as in part 13.
17. EXAMINE the Test Oscilloscope display for DC.

Examining AC POLARITY.
18. Change the following 370B settings:

COLLECTOR SUPPLY AC
POLARITY
VARIABLECOLLECTOR 100 %
SUPPLY

19. EXAMINE the display for a horizontal trace starting from graticule center
and extending out of the display area.

Examining - POLARITY.
20. Change the following 370B settings:

COLLECTOR SUPPLY -
POLARITY
VARIABLECOLLECTOR 100 %
SUPPLY

21. EXAMINE the display for a horizontal trace extending along the top
horizontal graticule line from the upper right corner.

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 Performance Verification

Examining -DC POLARITY.

22. Change the following 370B setting:

COLLECTOR SUPPLY - DC
POLARITY

23. EXAMINE the display for the spot to position the peak of part 21.
24. EXAMINE the Test Oscilloscope display for DC.

Examining -LEAKAGE POLARITY.

25. Change the following 370B setting:

COLLECTOR SUPPLY - LEAKAGE

POLARITY

26. EXAMINE the display for the spot to position the same as part 23.
27. EXAMINE the Test Oscilloscope display for DC.

Removing the Setup.

28. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

29. Disconnect the Test Oscilloscope.

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Performance Verification

G6. Examining the NOTE. The characteristics examined in this step are examples of typical
LIMITER Indicator in instrument operation; they are not specifications.
Voltage Mode

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
COLLECTOR SUPPLY
MAX PEAK VOLTS 400
OUTPUTS ENABLED
ProtectiveCover Closed

Examining the Limiter Indicator for 400 MAX PEAK VOLTS Range.
1. EXAMINE the LIMITER indicator besides the LEFT-RIGHT-STANDBY
for turn on when the VARIABLE COLLECTOR SUPPLY control is rotated
clockwise.

Examining the Limiter Indicator for 2000 MAX PEAK VOLTS Range.
2. Change the following 370B settings:

COLLECTOR SUPPLY
MAX PEAK VOLTS 2000
MAX PEAK POWER 2
WATTS

3. EXAMINE the LIMITER indicator for turn on when the VARIABLE

COLLECTOR SUPPLY control is rotated clockwise.

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 Performance Verification

4. Change the following 370B setting:

HORIZONTAL VOLTS/DIV 5 V COLLECTOR

5. EXAMINE the LIMITER indicator for turn on when the VARIABLE

COLLECTOR SUPPLY control is rotated clockwise.

G7. Examining the NOTE. The characteristics examined in this step are examples of typical
LIMITER Indicator in instrument operation; they are not specifications.
Current Mode

To LeftCOLLECTOR

PatchCord

To LeftEMITTER

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
VERTICAL CURRENT/DIV 100A COLLECTOR
COLLECTOR SUPPLY
MAX PEAK VOLTS 400
OUTPUTS ENABLED
LEFT-RIGHT-STANDBY LEFT
ProtectiveCover Closed

Examining the Limiter for 0.08 MAX PEAK POWER WATTS Range.
1. EXAMINE that the LIMITER indicator next to the LEFT-RIGHT-STAND-
BY lights when the VARIABLE COLLECTOR SUPPLY control is rotated
clockwise and watch for the peak of the trace to be brightening.

370B Service Manual 5-117

Performance Verification

Examining the Limiter for 0.4 MAX PEAK POWER WATTS Range.
2. Change the following 370B settings:

DISPLAY
VERTICAL CURRENT/DIV 500 A COLLECTOR
COLLECTOR SUPPLY
MAX PEAK POWER 0.4
WATTS

3. EXAMINE that the LIMITER indicator lights when the VARIABLE

COLLECTOR SUPPLY control is rotated clockwise and that the peak of the
trace brightens.

Examining the Limiter for 10 MAX PEAK POWER WATTS Range.

4. Change the following 370B settings:

DISPLAY
VERTICAL CURRENT/DIV 5 mA COLLECTOR
COLLECTOR SUPPLY
MAX PEAK POWER 10
WATTS

5. EXAMINE that the LIMITER indicator lights when the VARIABLE

COLLECTOR SUPPLY control is rotated clockwise and that the peak of the
trace brightens.

Removing the Setup.

6. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

7. Remove the Patch Cord from the 370B.

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 Performance Verification

AUX Supply
Equipment Required (see Table 5-3):
H Test Oscilloscope
H Digital Multimeter

H1. Checking AUX n

SUPPLY Accuracy,
Specifications:
Resolution, and Range
H The Aux Supply is accurate to less than (50 mV + 1.5 % of the total output).
H Resolution is 20 mV.
H Range is from - 40 V to + 40 V.

DigitalMultimeter

To AUX SUPPLY OUT

To 370B GroundJack

370B settings:
Initializethe 370B; thenset the followingcontrolas
indicated.
OUTPUTS ENABLED
ProtectiveCover Closed
Test EquipmentSettings:
DigitalMultimeterMode DC Voltage

370B Service Manual 5-119

Performance Verification

Checking Accuracy.
1. CHECK that the AUX SUPPLY readout on the 370B display is 0.00 V.
(AUX SUPPLY will not show on screen for 0.00 V.)
2. CHECK that the digital multimeter reading is within the limits given in
Table 5-18 for 0.00 V.

Table 5-18: Auxiliary Supply Accuracy

AUX readout Digital Multimeter Reading
0.00 V (no display)
0.05 V
+40.00 V +39.35 V to +40.65 V
-40.00 V -40.65 V to -39.35 V

Checking Resolution.
3. CHECK that each time one of the AUX SUPPLY arrow buttons (up or
down) is pressed, the AUX SUPPLY readout and digital multimeter reading
change by 20 mV.

Checking Range.
4. Change the following 370B setting:

AUX SUPPLY -40.00 V (as indicatedin

the AUX SUPPLY readout)

5. CHECK that the digital multimeter measurement is within the limits given
in Table 5-18 for -40.00 V.
6. Change the following 370B setting:

AUX SUPPLY +40.00 V (as indicatedin

the AUX SUPPLY readout)

7. CHECK that the digital multimeter measurement is within the limits given
in Table 5-18 for +40.00 V

Removing the Setup.

8. Disconnect the digital multimeter leads from the 370B.

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 Performance Verification

H2. Checking AUX n

SUPPLY Ripple and Noise
Specification:
H Displayed Ripple and Noise is less than 50 mV peak to peak.

To LEFT COLLECTOR To AUX SUPPLY OUT

PatchCord

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
DISPLAY
Mode NON STORE
HORIZONTAL VOLTS/DIV 50 mV COLLECTOR
COLLECTOR SUPPLY
POLARITY AC
LEFT-RIGHT-STANDBY LEFT

Checking Ripple and Noise.

1. CHECK that the spot width is within 1 horizontal division.

Removing the Setup.

2. Disconnect the patch cord from the 370B.

370B Service Manual 5-121

Performance Verification

Configuration
Equipment Required (see Table 5-3):
H Test Oscilloscope
H Digital Multimeter

I1. Examining Collector NOTE. The characteristics examined in this step are examples of typical
Configuration instrument operation; they are not specifications.

The following procedure checks operation of the relays that carry the Collector
Supply to the Test Fixture Adapter Jacks.

Test Oscilloscope

GND
VerticalInput
To LeftCollector

To 370B GroundJack

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
LEFT-RIGHT-STANDBY LEFT
OUTPUTS ENABLED
Test EquipmentSettings:
Test Oscilloscope:
VerticalSensitivity 5 V/divDC
HorizontalScale 2ms/div
TriggerMode Auto
TriggerSource Line

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 Performance Verification

Examining Internal Operation for LEFT.

1. Connect a test lead with a banana plug to the LEFT C(Collector) jack.
Connect a Probe hook from the Test Oscilloscope to the test leads clip, and
ground lead to the Ground plug.
2. Close the Protective Cover and turn the VARIABLE COLLECTOR
SUPPLY control.
3. EXAMINE the test oscilloscope for rectified waveform to be displayed.
4. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

5. EXAMINE the test oscilloscope for no waveform to be displayed.

A small waveform may be displayed by stray capacitance.

Examining Internal Operation for RIGHT.

6. Move the test lead with banana plug to the RIGHT C(Collector) and close
the Protective Cover.
7. EXAMINE the test oscilloscope for no waveform to be displayed.
A small waveform may be displayed by stray capacitance.
8. Change the following 370B setting:

LEFT-RIGHT-STANDBY RIGHT

9. EXAMINE the test oscilloscope for rectified waveform to be displayed.

Examining the Collector for OPEN.

10. Change the following 370B setting:

CONFIGURATION COLLECTOR OPEN

VARIABLECOLLECTOR 100 %
SUPPLY

11. EXAMINE the test oscilloscope for no waveform display.

A small waveform may be displayed by stray capacitance.

370B Service Manual 5-123

Performance Verification

Removing the Setup.

12. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

13. Disconnect the test lead and probe from the 370B.

I2. Examining Base NOTE. The characteristics examined in this step are examples of typical
Configuration instrument operation; they are not specifications.

The following procedure checks operation of the relays that carry the Step
Generator signal and Collector Supply to the Test Fixture Adapter Jacks.

Test Oscilloscope

GND
VerticalInput

ToLEFT BASE

To 370B GroundJack

370B settings:
Initializethe 370B; thenset the followingcontrolsas
indicated.
STEP GENERATOR
Mode VOLTAGE
STEP AMPLITUDE 2V
LEFT-RIGHT-STANDBY LEFT
OUTPUTS ENABLED
ProtectiveCover Closed

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 Performance Verification

Test EquipmentSettings:
Test Oscilloscope:
VerticalSensitivity 5 V/divDC
Horizontal 10 ms/div
TriggerMode Auto
TriggerSlope -

Examining Internal Operation for LEFT.

1. EXAMINE the test oscilloscope display for a step waveform.
2. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

3. EXAMINE the test oscilloscope for no step waveform display.

A small waveform may be displayed by stray capacitance.

Examining Internal Operation for RIGHT.

4. Connect the test oscilloscope between the RIGHT B(BASE) and ground
jacks, and close the protective cover
5. EXAMINE the test oscilloscope for no step waveform display.
A small waveform may be displayed by stray capacitance.
6. Change the following 370B setting:

LEFT-RIGHT-STANDBY RIGHT

7. EXAMINE the test oscilloscope for a step waveform to be displayed.

Examining External Base Input.

8. Change the following 370B setting:

CONFIGURATION BASE OPEN (EXT)

9. EXAMINE the test oscilloscope for no step waveform display.

10. Use a patch cord to connect the STEP GEN OUT and EXT BASE or
EMITTER IN jacks, and close the protective cover.

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Performance Verification

11. EXAMINE the test oscilloscope for a step waveform to be displayed.

Checking Base SHORT (EMITTER) Configuration.

12. Disconnect the patch cord and connect the test oscilloscope between the
STEP GEN OUT and ground jacks.
13. Change the following 370B and Test Equipment settings:

370B:
CONFIGURATION BASE SHORT (EMITTER)
ProtectiveCover Closed
Test EquipmentSettings:
Mode

14. EXAMINE the test oscilloscope does not display a step waveform.
15. Disconnect the Test Oscilloscope and connect the Digital Multimeter to the
RIGHT B(BASE) and E(EMITTER) jacks.
16. EXAMINE that the RIGHT B and E are shorted.
Resistance is approximately 1
or less.
17. Change the following 370B setting:

LEFT-RIGHT-STANDBY LEFT

18. Connect the Digital Multimeter to the LEFT B(BASE) and E(EMITTER)
jacks.
19. EXAMINE that the LEFT B and E are shorted.
Resistance is approximately 1
or less.

Checking Base COLLECTOR SUPPLY CONFIGURATION.

20. Disconnect the Digital Multimeter.
21. Change the following 370B and Test Equipment settings:

370B:
CONFIGURATION BASE COLLECTOR SUP-
PLY
OUTPUT ENABLED

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 Performance Verification

Test Oscilloscope:
VerticalSensitivity 5 V/divDC
Horizontal 2 ms/div
TriggerMode Line

22. Connect a test leads with banana plug to the LEFT B jack. Connect a probe
hook from the Test Oscilloscope to the test lead clip, and the ground lead to
to the Ground jack.
23. Close the Protective Cover and turn the VARIABLE COLLECTOR
SUPPLY control.
24. EXAMINE the test Oscilloscope for rectified waveform to be displayed.

Removing the Setup.

25. Change the following 370B setting:

LEFT-RIGHT-STANDBY STANDBY

26. Disconnect the Test Lead and Probe from the 370B.

I3. Examining Emitter NOTE. The characteristics examined in this step are examples of typical
Configuration instrument operation; they are not specifications.

Test Oscilloscope

GND
VerticalInput

ToLEFT EMITTER

To 370B GroundJack

370B settings:

370B Service Manual 5-127

Performance Verification

Initializethe 370B; thenset the followingcontrolsas

indicated.
STEP GENERATOR
Mode VOLTAGE
STEP AMPLITUDE 1V
CONFIGURATION EMITTER STEP GEN
OUTPUTS ENABLED
ProtectiveCover Closed
Test EquipmentSettings:
Test Oscilloscope:
VerticalSensitivity 2 V/divDC
Horizontal 10 ms/div
TriggerMode Auto
TriggerSlope +

Examining Internal Operation for LEFT.

1. EXAMINE the test oscilloscope display for a step waveform.

Examining Internal Operation for RIGHT.

2. Connect the test oscilloscope between the RIGHT E (Emitter) and ground
jacks and close the protective cover.
3. EXAMINE the test oscilloscope display for a step waveform.

Examining External Operation.

4. Change the following 370B setting:

CONFIGURATION EMITTER OPEN (EXT)

5. EXAMINE the test oscilloscope for no step waveform display.

6. Use a patch cord to connect the STEP GEN OUT and EXT BASE or
EMITTER IN jacks, and close the protective cover.
7. EXAMINE the test oscilloscope display for a step waveform.

Removing the Setup.

8. Disconnect the test oscilloscope and remove the patch cord from the 370B.

5-128 370B Service Manual

 Performance Verification

Key Operation and Floppy Disk Drive

Equipment Required (see Table 5-3):
H 2HD Floppy Disk

J1. Examining Key NOTE. The characteristics examined in this step are examples of typical
Operation instrument operation;they are not specifications.

370B settings:
Initialsetting

Examining Key Operation.

1. Simultaneously press the FAST/SHIFT and the POSITION DISPLAY
buttons to enter “KEY CHECK MODE”.
2. EXAMINE all buttons and knobs while pressing or turning them to change
the display.
Except the INTENSITY, FOCUS, GRAT ILLUM, POSITION, and TRACE
ROTATION controls.
3. Simultaneously press the FAST/SHIFT and the POSITION DISPLAY
buttons to exit “KEY CHECK MODE”.

370B Service Manual 5-129

Performance Verification

J2. Examining Floppy Disk NOTE. The characteristics examined in this step are examples of typical
Drive Operation instrument operation;they are not specifications.

Disk Slot

FloppyDisk

370B settings:
Initialsetting

Installing the Floppy Disk.

1. Set the write-protect tab of the floppy disk to write-enable position.
2. Install the floppy disk in the floppy disk slot of the 370B.

CAUTION. The following step for data formatting will erase all data on the
floppy disk.

Formatting the Floppy Disk.

3. Press the SAVE/FORMAT button while holding down the FAST/SHIFT
button, then press the SAVE/FORMAT button.
4. EXAMINE the “FORMAT END” message is displayed after formatting.

Examining Read Write Operation.

5. Press the RECALL/DIRECTORY button while holding down the
FAST/SHIFT button.
6. Press the up MEMORY button to set the DIRECTORY PAGE to 7.

5-130 370B Service Manual

 Performance Verification

7. EXAMINE the <READ ERROR> message is not displayed at any of the

memory locations.
8. EXAMINE the <READ ERROR> message is not displayed at any of the
memory locations when repeating steps 6 and 7 from DIRECTORY PAGE 8
to 28.
9. Press the STORE button to exit from the directory display mode.

370B Service Manual 5-131

Performance Verification

5-132 370B Service Manual

Instrument Options
Options and Accessories

Options
This subsection describes the following options available with the 370B
Programmable Curve Tracer.
H Option 1R (Rack mounting)
H Option D1 (Test result report)
H Option A9 (No power cord supplied)

Option 1R 370B Programmable Curve Tracer comes configured for installation in a 19-inch
wide instrument rack.

Option D1 A calibration data test result report will be provided with the 370B Program-
mable Curve Tracer when this option is specified.

Option A9 370B Programmable Curve Tracer comes without the power cord.

370B Service Manual 6-1

Options and Accessories

Accessories
Standard Accessories The 370B Programmable Curve Tracer includes the standard accessories listed in
Table 6-1:

Table 6-1: Standard accessories

Accessory Part number

User Manual(English) 070-A838-XX
Fuse
250 V, 2 A, Medium-blow 159-0260-00
125 V, 4 A, Medium-blow 159-0259-00
ProtectiveCover 337-3344-02
UtilitySoftware(FDD) 063-3341-XX
PowerCord 161-0066-00
Test Adapters
BlankAdapter A1001
In-lineAdapter A1002
AxialLead Adapter A1005

Optional Accessories The following optional accessories, listed in Table 6-2, are recommended for use
with the instrument:

Table 6-2: Optional accessories

Accessory Part number

ServiceManual 070-A842-XX
Test Adapter
TO-3/TO-66 Adapter A1003
4 and 6 Lead TransistorAdapter A1007
4 and 6 Lead FET Adapter A1009
IC Adapter A1010
SOT23, SMD Adapter A1023
GPIB Cable, 2m 012-0991-00
Rack MountKit 016-0930-00
Cart K475

This appendix describes the various options as well as the standard and optional
accessories that are available for the 370B Programmable Curve Tracer.

6-2 370B Service Manual

 Options and Accessories

Recommended The following optional accessories, listed in Table 6-3, are recommended for use
Accessories with the instrument:

Table 6-3: Recommended accessories

Accessory Model number

ThermalPrinter iDP3240
CBM, ThermalPrinter
(http://www.jcbm.co.jp)

370B Service Manual 6-3

Options and Accessories

6-4 370B Service Manual

Electrical Parts List
Replaceable Electrical Parts

The modules that make up this instrument are often a combination of mechanical
and electrical subparts. Therefore, all replaceable modules are listed in section,
Mechanical Parts List. Refer to that section for part numbers when using this
manual.
The repair of the 370B Programmable Curve Tracer is the exchange of the board
fundamentally.

This section contains a list of the electrical components for the 370B Program-
mable Curve Tracer. Use this list to identify and order replacement parts.

Parts Ordering Information

Replacement parts are available through your local Tektronix field office or
representative.
Changes to Tektronix products are sometimes made to accommodate improved
components as they become available and to give you the benefit of the latest
improvements. Therefore, when ordering parts, it is important to include the
following information in your order.
H Part number (see Part Number Revision Level below)
H Instrument type or model number
H Instrument serial number
H Instrument modification number, if applicable
If you order a part that has been replaced with a different or improved part, your
local Tektronix field office or representative will contact you concerning any
change in part number.
Change information, if any, is located at the rear of this manual.

Part Number Revision Tektronix part numbers contain two digits that show the revision level of the
Level part. For most parts in this manual, you will find the letters XX in place of the
revision level number.

370B Service Manual 7-1

Electrical Parts List

Part NumberRevisionLevel RevisionLevelMay Showas XX

670-7918-03 670-7918-XX

When you order parts, Tektronix will provide you with the most current part for
your product type, serial number, and modification (if applicable). At the time of
your order, Tektronix will determine the part number revision level needed for
your product, based on the information you provide.

Using the Replaceable Electrical Parts List

The tabular information in the Replaceable Electrical Parts List is arranged for
quick retrieval. Understanding the structure and features of the list will help you
find all of the information you need for ordering replacement parts. The
following table describes each column of the electrical parts list.

Parts List Column Descriptions

Column Column Name Description

1 ComponentNumber The componentnumberappearson diagramsand circuitboardillustrations,locatedin the diagrams
section.Assemblynumbersare clearlymarkedon each diagramand circuitboardillustrationin the
Diagrams section,and on the mechanicalexplodedviewsin the Replaceable Mechanical Parts list
section.The componentnumberis obtainedby addingthe assemblynumberprefixto the circuit
number(see ComponentNumberillustrationfollowingthistable).
The electricalpartslistis arrangedby assembliesin numericalsequence(A1, withitssubassem-
bliesand parts,precedesA2, withitssubassembliesand parts).
Chassis-mountedpartshave no assemblynumberprefix,and theyare locatedat the end of the
electricalpartslist.
2 TektronixPart Number Use thispartnumberwhenorderingreplacementpartsfromTektronix.
3 and 4 SerialNumber Columnthreeindicatesthe serialnumberat whichthe partwas firsteffective.Columnfourindicates
the serialnumberat whichthe partwas discontinued.No entryindicatesthe partis goodforall
serialnumbers.
5 Name & Description An itemname is separatedfromthe descriptionby a colon(:). Becauseof spacelimitations,an item
name may sometimesappearas incomplete.Use the U.S. FederalCataloghandbookH6-1 for
furtheritemname identification.
6 Mfr. Code Thisindicatesthe codenumberof the actualmanufacturerof the part.
7 Mfr. Part Number Thisindicatesthe actualmanufacturer’s or vendor’s partnumber.

7-2 370B Service Manual

 Electrical Parts List

Abbreviations Abbreviations conform to American National Standard ANSI Y1.1-1972.

Component Number ComponentNumber

A23A2R1234 A23 A2 R1234

Assemblynumber SubassemblyNumber CircuitNumber

(optional)
Read: Resistor 1234 (of Subassembly 2) of Assembly 23

List of Assemblies A list of assemblies is located at the beginning of the electrical parts list. The
assemblies are listed in numerical order. When a part’s complete component
number is known, this list will identify the assembly in which the part is located.

Chassis Parts Chassis-mounted parts and cable assemblies are located at the end of the
Replaceable Electrical Parts List.

Mfr. Code to Manufacturer The table titled Manufacturers Cross Index shows codes, names, and addresses
Cross Index of manufacturers or vendors of components listed in the parts list.

Manufacturers cross index

Mfr.
code Manufacturer Address City, state, zip code
TK0191 TEKTRONIX JAPAN, Ltd 5 - 9 - 31 KITASHINAGAWA, TOKYO JAPAN 141 - 0001
SHINAGAWA- KU, TOKYO
80009 TEKTRONIX INC 14150 SW KARL BRAUN DR BEAVERTON OR 97077 - 0001
PO BOX 500

370B Service Manual 7-3

Electrical Parts List

Replaceable electrical parts list

Component Tektronix part Serial no. Serial no. Mfr.

number number effective discont’d Name & description code Mfr. part number
A1 671 - 0236 - 02 CIRCUIT BD ASSY:MOTHER 80009 671023602
A2 671 - B126- 01 CIRCUIT BD ASSY:CPU 80009 671B12601
A3 671 - B213- 00 CKT BD ASSY:A/D 80009 671B21300
A4 670 - 9306 - 04 CIRCUIT BD ASSY:DIGITAL DISPLAY 80009 670930604
A5 670 - 9307 - 05 CIRCUIT BD ASSY:DISPLAY CONTROL 80009 670930705

A6 670 - 9308 - 06 CIRCUIT BD ASSY:COLLECTOR SUPPLY 80009 670930806

A7 670 - 9309 - 09 CIRCUIT BD ASSY:STEP GENERATOR 80009 670930909
A9 671 - 1183 - 04 CIRCUIT BD ASSY:LV RELAY 80009 671118304
A10 671 - B212- 00 CIRCUIT BD ASSY:SENSE BOARD 80009 671B21200
A11 671 - B235- 00 CIRCUIT BD ASSY:MAIN KEY 80009 671B23500

A12 671 - 1149 - 02 CIRCUIT BD ASSY:SUB KEY 80009 671114902

A13 671 - 1238 - 02 CIRCUIT BD ASSY:KEY INTERFACE 80009 671123802
A14 671 - B244- 00 CIRCUIT BD ASSY:LOR KEY 80009 671B24400
A15 671 - B245- 00 CIRCUIT BD ASSY:CONFIGURATION LED 80009 671B24500
A18 670 - 9319 - 02 CIRCUIT BD ASSY:CRT OUTPUT 80009 670931902

A19 670 - 9320 - 01 CIRCUIT BD ASSY:LV SUPPLY 80009 670932001

A20 670 - B211 - 00 CIRCUIT BD ASSY:H.V. REGULATOR TK0191 670B21100
A22 671 - B127- 01 CIRCUIT BD ASSY:INTERFACE 80009 671B12701
A23 671 - B128- 01 CIRCUIT BD ASSY:FDD INTERFACE 80009 671B12801
A24 119 - B105- 00 FLOPPY DISK UNI:3.5 INCH W/INTERFACE 80009 119B10500
(STANDARD ACCESSORY)

A27 670 - 9323 - 00 CIRCUIT BD ASSY:PRIMARY 80009 670932300

A28 670 - 9324 - 02 CIRCUIT BD ASSY:LAMP 80009 670932401
A29 670 - 9324 - 02 CIRCUIT BD ASSY:LAMP 80009 670932402
A33 671 - 1096 - 03 CIRCUIT BD ASSY:CONFIGURATION RELAY 80009 671109603
A34 671 - 1140 - 01 CIRCUIT BD ASSY:LOR RELAY 80009 671114001

A35 671 - 1147 - 03 CIRCUIT BD ASSY:LOOPING 80009 671114703

7-4 370B Service Manual

 Electrical Parts List

Replaceable electrical parts list (Cont.)

Component Tektronix part Serial no. Serial no. Mfr.

number number effective discont’d Name & description code Mfr. part number
A1W60 174 - 0291 - 00 CA ASSY,SP,ELEC:16,28 AWG,18.5 L,RIBBON 80009 174029100
A1W70 174 - 0292 - 00 CA ASSY,SP,ELEC:16,28 AWG,4.3 L,RIBBON 80009 174029200

A1W192 174 - 0294 - 00 CA ASSY,SP,ELEC:16,28 AWG,12.6 L,RIBBON 80009 174029400

A6W64 174 - 0301 - 00 CA ASSY,SP,ELEC:4,22 AWG,16.0 L 80009 174030100

A6W66 174 - 0304 - 00 CA ASSY,SP,ELEC:2,26 AWG,6.0 L,RIBBON 80009 174030400

A9W90 174 - 1774 - 00 CA ASSY,SP,ELEC:40,26 AWG,8.0 L,RIBBON 80009 174177400

A11W110 174 - 0293 - 00 CA ASSY,SP,ELEC:40,28 AWG,4.3 L,RIBBON 80009 174029300

A14W140 174 - 1832 - 00 CA ASSY,SP,ELEC:14,28 AWG,23.0 L,RIBBON 80009 174183200

A15W150 174 - 1775 - 00 .301393 .301497 CA ASSY,SP,ELEC:16,26 AWG,18.0 L,RIBBON 80009 174177500
A15W150 174 - 1775 - 01 .301498 CA ASSY,SP,ELEC:16,28 AWG,250MM L,RIBBON 80009 174177501

A22W220 174 - 0295 - 00 CA ASSY,SP,ELEC:26,28 AWG,11.0 L,RIBBON 80009 174029500

A23W100 174 - 1692 - 00 CA ASSY,SP,ELEC:24,28 AWG,12.0 L,RIBBON 80009 174169200

A23W200 174 - 1611 - 00 CA ASSY,SP,ELEC:34,28 AWG,9.0 L,RIBBON 80009 174161100

A33W330 174 - 1951 - 00 CA ASSY,SP,ELEC:14,28 AWG,11.0 L,RIBBON 80009 174195100

370B Service Manual 7-5

Electrical Parts List

Replaceable electrical parts list (Cont.)

Component Tektronix part Serial no. Serial no. Mfr.

number number effective discont’d Name & description code Mfr. part number
B100 119 - 3674 - 00 .301393 .32156 FAN,TUBEAXIAL:115 VAC,240MA,19W,2650 RPM 80009 119367400
B100 119 - 2310 - 01 .302157 FAN,TUBEXIAL:115VAC,230MA,16W,2650RPM 80009 119231001
F100 159 - 0259 - 00 FUSE , CARTRIDGE :4A, 125V, MEDIUM 80009 159025900
(115V ONLY)
F100 159 - 0260 - 00 FUSE , CARTRIDGE :2A, 250V, MEDIUM 80009 159026000
(230V ONLY)
W3 198 - 5683 - 00 WIRE SET, ELEC: 80009 198568300
W4 198 - 5700 - 00 WIRE SET, ELEC: 80009 198570000
W14 196 - 3099 - 00 LEAD, ELECTRICAL:24 AWG, I0.0 L 80009 196309900
W16 196 - 3110 - 00 LEAD,ELECTRICAL: 18 AWG,7.0 L,8 - 9 80009 196311000
W17 196 - 3112 - 01 LEAD,ELECTRICAL: 18 AWG,6.0 L,5 - 4 80009 196311201
W18 196 - 3111 - 00 LEAD,ELECTRICAL: 18 AWG,7.0 L,8 - 9 80009 196311100
W19 196 - 3098 - 01 LEAD, ELECTRICAL: 18 AWG , 7.0 L,5 - 4 80009 196309801
W66 174 - 0304 - 00 CA ASSY,SP, ELEC :2,26 AWG,6.0 L, RIBBON 80009 174030400
W72 174 - 0310 - 00 CA ASSY,SP, ELEC :10,22 AWG, 1 8.0 L, RIBBON 80009 174031000
W91 198 - 5680 - 01 WIRE SET, ELEC: 80009 198568001
W93 198 - 5696 - 00 WIRE SET, ELEC: 80009 198569600
W95 198 - 5680 - 00 WIRE SET, ELEC: 80009 198568000
W102 198 - 5679 - 00 WIRE SET, ELEC: 80009 198567900
W103 198 - 5682 - 00 WIRE SET, ELEC: 80009 198568200
W104 198 - 5681 - 00 .301393 .301977 WIRE SET, ELEC: 80009 198568100
W104 198 - 5681 - 01 .301978 WIRE SET, ELEC: 80009 198568101
W111 196 - 3096 - 00 LEAD, ELECTRICAL: 18 AWG,3.5 L,5 - 4 80009 196309600
W142 174 - 1693 - 00 CA ASSY,SP,ELEC:34,28 AWG,1 30.0 L,RIBBON 80009 174169300
W180 174 - 0314 - 00 CA ASSY,SP,ELEC:9,26 AWG,7.5 L,RIBBON 80009 174031400
W182 174 - 0309 - 00 CA ASSY,SP, ELEC : I 0,22 AWG,5.0 L,RIBBON 80009 174030900
W190 174 - 0328 - 00 CA ASSY,SP,ELEC:4,18 AWG,15.5 L 80009 174032800
W194 174 - 0308 - 00 CA ASSY,SP,ELEC:6,22 AWG,20.0 L,RIBBON 80009 174030800
W210 198 - 5686 - 00 WIRE SET, ELEC : 80009 198568600
W270 174 - 0327 - 00 CA ASSY,SP,ELEC:2,18 AWG,7.0 L 80009 174032700
W272 161 - 0255 - 01 .301393 .301412 CABLE ASSY,PWR,:2,0.75MM SQ,250V,3A 80009 161025501
W272 198 - 5733 - 00 .301413 .301577 WIRE SET,ELEC: 80009 198573300
W272 161 - 0257 - 01 .301578 .302156 CABLE ASSY,PWR,:125V,1A.200MML 80009 161025701
W280 174 - 0313 - 00 CA ASSY,SP,ELEC:2,26 AWG,30.0 L,RIBBON 80009 174031300
W290 174 - 0312 - 00 CA ASSY,SP,ELEC:2,26 AWG,22.0 L,RIBBON 80009 174031200
W400 174 - 0296 - 00 CA ASSY,SP, ELEC :34,28 AWG,5.5 L, RIBBON 80009 174029600
W401 198 - 5685 - 00 WI RE SET, ELEC : 80009 198568500
W402 196 - 3270 - 00 LEAD, ELECTRICAL:26 AWG,28.0 L, N - 0 80009 196327000
W410 198 - 5468 - 00 WIRE SET,ELEC : 80009 198546800
W490 198 - 5714 - 00 WIRE SET, ELEC :W/D - SUB CONN 80009 198571400
W491 198 - 5713 - 00 WIRE SET, ELEC :W/D - SUB CONN 80009 198571300

7-6 370B Service Manual

Diagrams
 Figure 8- 1: 370B circuit board locator

370B Service Manual Circuit Board Interconnections 1 8- 1

8- 2 370B Service Manual
370B Service Manual 8- 3
8- 4 370B Service Manual
370B Service Manual 8- 5
8- 6 370B Service Manual
 J310
Establishment in shipping is pin 1 and 2 are connected .
(PULSED OFFSET MODE)
J310 is changed to make DC OFFSET MODE.
( pin 2 and 3 are connected .)

TP658

370B Service Manual Test Point and Adjustment Locations 1 8- 7

 R325 R224
CURRENT LOOP
BALANCE GAIN

R310
SG ZERO
R238
LOOPING
BALANCE

8- 8 Test Point and Adjustment Locations 2 370B Service Manual

370B Service Manual Test Point and Adjustment Locations 3 8- 9
8- 10 370B Service Manual
370B Service Manual Troubleshooting Tree 8- 11
8- 12 Troubleshooting Tree (cont.) 370B Service Manual
370B Service Manual Troubleshooting Tree (cont.) 8- 13
8- 14 Troubleshooting Tree (cont.) 370B Service Manual
370B Service Manual Troubleshooting Tree (cont.) 8- 15
8- 16 Troubleshooting Tree (cont.) 370B Service Manual
370B Service Manual Troubleshooting Tree (cont.) 8- 17
8- 18 Troubleshooting Tree (cont.) 370B Service Manual
370B Service Manual Troubleshooting Tree (cont.) 8- 19
8- 20 Troubleshooting Tree (cont.) 370B Service Manual
Mechanical Parts List
Mechanical Parts List

This section contains a list of the replaceable modules for the 370B. Use this list
to identify and order replacement parts.

Parts Ordering Information

Replacement parts are available through your local Tektronix field office or
representative.
Changes to Tektronix instruments are sometimes made to accommodate
improved components as they become available and to give you the benefit of
the latest circuit improvements. Therefore, when ordering parts, it is important to
include the following information in your order.
H Part number (see Part number Revision Level below)
H Instrument type or model number
H Instrument serial number
H Instrument modification number, if applicable
If you order a part that has been replaced with a different or improved part, your
local Tektronix field office or representative will contact you concerning any
change in part number.
Change information, if any, is located at the rear of this manual.

Part Number Revision Tektronix part numbers contain two digits that show the revision level of the
Level part. For most parts in this manual, you will find the letters XX in place of the
revision level number.

Part NumberRevisionLevel RevisionLevelmay showas XX

670-7918-03 670-7918-XX

When you order parts, Tektronix will provide you with the most current part for
your product type, serial number, and modification (if applicable). At the time of
your order, Tektronix will determine the part number revision level needed for
your product, based on the information you provide.

370B Service Manual 9-1

Mechanical Parts List

Module Servicing Modules can be serviced by selecting one of the following three options. Contact
your local Tektronix service center or representative for repair assistance.

Module Exchange. In some cases you may exchange your module for a reman-
ufactured module. These modules cost significantly less than new modules and
meet the same factory specifications. For more information about the module
exchange program, call 1-800-TEK-WIDE, extension 6630.

Module Repair and Return. You may ship your module to us for repair, after which
we will return it to you.

New Modules. You may purchase replacement modules in the same way as other
replacement parts.

Using the Replaceable Parts List

This section contains a list of the mechanical and/or electrical components that
are replaceable for the analyzer. Use this list to identify and order replacement
parts. The following table describes each column in the parts list.

Parts List Column Descriptions

Column Column Name Description

1 Figure& IndexNumber Itemsin thissectionare referencedby componentnumber.
2 TektronixPart Number Use thispartnumberwhenorderingreplacementpartsfromTektronix.
3 and 4 SerialNumber Columnthreeindicatesthe serialnumberat whichthe partwas firsteffective.Columnfour
indicatesthe serialnumberat whichthe partwas discontinued.No entriesindicatesthe partis
goodforall serialnumbers.
5 Qty Thisindicatesthe quantityof partsused.
6 Name & Description An itemname is separatedfromthe descriptionby a colon(:). Becauseof spacelimitations,an
itemname may sometimesappearas incomplete.Use the U.S. FederalCataloghandbook
H6-1 forfurtheritemname identification.
7 Mfr. Code Thisindicatesthe codeof the actualmanufacturerof the part.(Code to name and addresscross
referenceis locatedafterthispage.)
8 Mfr. Part Number Thisindicatesthe actualmanufacturer’s or vendor’s partnumber.

Abbreviations Abbreviations conform to American National Standard ANSI Y1.1-1972.

Mfr. Code to Manufacturer The following table cross indexes codes, names, and addresses of manufacturers
Cross Index or vendors of components listed in the parts list.

9-2 370B Service Manual

 Mechanical Parts List

Manufacturers cross index

Mfr.
code Manufacturer Address City, state, zip code
S3109 FELLER 72 VERONICA AVE SUMMERSET NJ 08873
UNIT 4
TK0AR KITAGAWA IND CO LTD 2 - 4 - 26 MUROMACHI TOKYO JAPAN
NIHONBASHI CHUO - KU
TK0AU CHIYODA DENSHI CO LTD 2 - 5 - 12 MITA TOKYO JAPAN
MEGURO - KU
TK0BI ACOUS IND CO LTD 2 - 6 TA- CO KANDA TOKYO JAPAN
CHIYODA- KU
TK0BK SHOWA KOSAN CO LTD 2 - 947 IKEBUKURO TOKYO JAPAN
TOSHIMA- KU
TK0BV KYODO LIGHT METAL CO LTD 2 - 5 - 3 NIHONBASHI TOKYO JAPAN
CHUO - KU
TK0CB T K Y MFG CO LTD 2 - 18 - 8 MASUGATA KANAGAWA JAPAN
TAMA- KU KAWASAKI- CITY
TK0CF YASUDA MFG CO LTD 81 - 1 OKESHITA SHIZUOKA JAPAN
NISHIMAKADONUMAZU- CITY
TK0FB NIHON BURNDY 3 - 26 - 33 TAKANASA TOKYO JAPAN
MINATO - KU
TK00Z H Y ASSOCIATES CO LTD 1 - 2 - 2 MOMOI TOKYO JAPAN
SIGINAMI- KU
TK0191 TEKTRONIX JAPAN, Ltd 5 - 9 - 31 KITASHINAGAWA, TOKYO JAPAN 141 - 0001
SHINAGAWA- KU, TOKYO
TK0413 ADAMS SUPPLY COMPANY 1850 W 205TH ST TORRANCE CA 90509
P O BOX 2938
TK0435 LEWIS SCREW CO 4300 S RACINE AVE CHICAGO IL 60609 - 3320
TK0588 UNIVERSAL PRECISION PRODUCTS 1775 NW 216TH HILLSBOROOR 97123
TK1181 SEA- TAC INDUSTRIES INC 1217 FOURTH AVE N KENT WA 98031
TK1267 BALCKELECTRIC CORP P O BOX 50934 PALO ALTO CA 94303
TK1499 AMLAN INC 97 THORNWOOD RD STAMFORD CT 06903 - 2617
TK1665 PORTLAND DIE AND STAMPING INC 4805 SE 26TH PORTLAND OR 97202
TK1741 COLMAN FASTENERS CO LTD HATTONS ROAD MANCHESTER M17 1DF ENGLAND
OFF WESTINGHOUSE RD TRAFFORD PARK
TK1943 NEILSEN MANUFACTURING INC 3501 PORTLAND ROAD NE SALEM OR 97303
TK2541 AMERICOR ELECTRONICS LTD 2682 W COYLE AVENUE ELK GROVE VILLAGE IL 60007
TK2548 XEROX BUSINESS SERVICES 14181 SW MILLIKANWAY BEAVERTON OR 97077
DIV OF XEROX CORPORATION
0JR05 TRIQUEST CORP 3000 LEWIS AND CLARK HWY VANCOUVER WA 98661 - 2999
0KB01 STAUFFER SUPPLY 810 SE SHERMAN PORTLAND OR 97214
07416 NELSON NAME PLATE CO 3191 CASITAS LOS ANGELES CA 90039 - 2410
11897 PLASTIGLIDEMFG CORP 2701 W EL SEGUNDO BLVD HAWTHORNE CA 90250 - 3318
12136 P H C INDUSTRIES INC 1643 HADDON AVE CAMDEN NJ 08103 - 3109
PO BOX 1448
12327 FREEWAY CORP 9301 ALLEN DR CLEVELAND OH 44125 - 4632

370B Service Manual 9-3

Mechanical Parts List

Manufacturers cross index (Cont.)

Mfr.
code Manufacturer Address City, state, zip code
12697 CLAROSTAT MFG CO INC 12055 ROJAS DRIVE EL PASO, TX 79936
SUITE K
13103 THERMALLOY CO INC 2021 W VALLEY VIEW LN DALLASTX 75381
PO BOX 810839
73743 FISCHER SPECIAL MFG CO 111 INDUSTRIAL RD COLD SPRING KY 41076 - 9749
78189 ILLINOIS TOOL WORKS INC ST CHARLES ROAD ELGIN IL 60120
SHAKEPROOF DIV
8X345 NORTHWEST SPRING & MFG CO 5858 SW WILLOW LANE LAKE OSWEGO OR 97035
80009 TEKTRONIX INC 14150 SW KARL BRAUN DR BEAVERTON OR 97077 - 0001
PO BOX 500
83486 ELCO INDUSTRIES INC 1101 SAMUELSON RD ROCKFORD IL 61101
86928 SEASTROM MFG CO INC 701 SONORA AVE GLENDALE CA 91201 - 2431
93907 TEXTRON INC 600 18TH AVE ROCKFORD IL 61108 - 5181
CAMCAR DIV
99742 PERMACEL TAPE DIV U S HIGHWAY 1 NEW BRUNSWICK NJ 08903
AN AVERY CO P O BOX 671

9-4 370B Service Manual

 Mechanical Parts List

Replaceable mechanical parts list

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
1-1 390 - 0984 - XX 1 CABINET SIDE:LEFT 80009 3900984XX
(ATTACHING PARTS)
-2 211 - 0504 - XX 1 SCREW,MACHINE:6- 32 X 0.250,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
-3 367 - 0116 - XX 2 HANDLE,CARRYING:16.54 L,BLUEVINYL 12136 ORDER BY DESC
(ATTACHING PARTS)
-4 212 - 0628 - XX 8 SCREW,SHOULDER:10- 32 X 0.4 L,RDH,STL 93907 ORDER BY DESC
(END ATTACHING PARTS)
-5 386 - 1624 - XX 4 PLATE,HDL RTNG:STAINLESS STEEL TK1943 ORDER BY DESC
-6 386 - 1283 - XX 4 PLATE,HDL MTG:FRONT 0JR05 ORDER BY DESC
-7 200 - 0728 - XX 4 COVER,HDL END:1.91 X 0.91 X 0.36 BLUEACETAL 0JR05 200 - 0728 - XX
-8 426 - 2371 - XX 1 FRAME,SECTION:TOP LEFT,TEK TAN,AL 80009 4262371XX
(ATTACHING PARTS)
-9 211 - 0507 - XX 1 SCREW,MACHINE:6- 32 X 0.312,PNH,STL TK0435 ORDER BY DESC
- 10 211 - 0510 - XX 2 SCREW,MACHINE:6-32 X 0.375,PNH,STL TK0435 ORDER BY DESC
- 11 211 - 0538 - XX 5 SCREW,MACHINE:6- 32 X 0.312,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 12 124 - 0446 - XX 1 STRIP,TRIM:TOP RIGHT 80009 1240446XX
- 13 426 - 2372 - XX 1 FRAME,SECTION:TOP RIGHT,TEK TAN,AL 80009 4262372XX
(ATTACHING PARTS)
- 14 211 - 0507 - XX 1 SCREW,MACHINE:6-32 X 0.312,PNH,STL TK0435 ORDER BY DESC
- 15 211 - 0538 - XX 1 SCREW,MACHINE:6-32 X 0.312,FLH,STL TK0435 ORDER BY DESC
- 16 211 - 0510 - XX 2 SCREW,MACHINE:6-32 X 0.375,PNH,STL TK0435 ORDER BY DESC
- 17 211 - 0504 - XX 5 SCREW,MACHINE:6- 32 X 0.250,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 18 124 - 0447 - XX 1 STRIP,TRIM:TOP RIGHT 80009 1240447XX
- 19 426 - 2141- XX 1 FRAME SECT,CAB.:LEFT 80009 4262141XX
(ATTACHING PARTS)
- 20 211 - 0559 - XX 1 SCREW,MACHINE:6-32 X 0.375,FLH,STL TK0435 1593 - 300
- 21 211 - 0504 - XX 4 SCREW,MACHINE:6- 32 X 0.250,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 22 426 - 2142- XX 1 FRAME SECT,CAB.:RIGHT 80009 4262142XX
(ATTACHING PARTS)
- 23 211 - 0559 - XX 1 SCREW,MACHINE:6-32 X 0.375,FLH,STL TK0435 1593 - 300
- 24 211 - 0504 - XX 3 SCREW,MACHINE:6- 32 X 0.250,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 25 407 - 3890 - XX 1 BRACKET,SUPPORT:ALUMINUM 80009 4073890XX
(ATTACHING PARTS)
- 26 212 - 0002 - XX 4 SCREW,MACHINE:8- 32 X 0.25,FLH,100 DEG,STL 0KB01 ORDER BY DESC
- 27 212 - 0004 - XX 4 SCREW,MACHINE:8- 32 X 0.312,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 28 407 - 3890 - XX 1 BRACKET,SUPPORT:ALUMINUM 80009 4073890XX
(ATTACHING PARTS)

370B Service Manual 9-5

Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
- 29 212 - 0002 - XX 4 SCREW,MACHINE:8- 32 X 0.25,FLH,100 DEG,STL 0KB01 ORDER BY DESC
- 30 212 - 0004 - XX 4 SCREW,MACHINE:8- 32 X 0.312,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 31 334 - 7747 - XX 1 MARKER,IDENT: 80009 3347747XX
- 32 426 - 2211 - XX 1 FRAME SECTION:BOTTOM,LEFT TK0191 ORDER BY DESC
(ATTACHING PARTS)
- 33 211 - 0559 - XX 2 SCREW,MACHINE:6- 32 X 0.375,FLH,STL TK0435 1593 - 300
(END ATTACHING PARTS)
- 34 124 - 0448 - XX 2 STRIP,TRIM:BOTTOM 80009 1240448XX
- 35 348 - 0128 - XX 4 FOOT,CABINET:BLACKPOLYURETHANE 80009 3480128XX
(ATTACHING PARTS)
- 36 211 - 0513 - XX 8 SCREW,MACHINE:6- 32 X 0.625,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 37 426 - 2134 - XX 1 FRAME SECTION:FRONT,LEFT TK0191 4262134XX
(ATTACHING PARTS)
- 38 211 - 0538 - XX 2 SCREW,MACHINE:6- 32 X 0.312,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 39 426 - 2138 - XX 1 FRAME SECTION:BOTTOM,RIGHT TK0191 4262138XX
(ATTACHING PARTS)
- 40 211 - 0559 - XX 2 SCREW,MACHINE:6- 32 X 0.375,FLH,STL TK0435 1593 - 300
(END ATTACHING PARTS)
- 41 334 - 3379 - XX 1 MARKER,IDENT:MARKEDGROUND SYMBOL 07416 ORDER BY DESC
- 42 426 - 2135 - XX 1 FRAME SECTION:FRONT,RIGHT TK0191 4262135XX
(ATTACHING PARTS)
- 43 211 - 0538 - XX 2 SCREW,MACHINE:6- 32 X 0.312,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 44 351 - 0770 - XX 2 GUIDE,TEST FXTR:BOTTOM 80009 3510770XX
(ATTACHING PARTS)
- 45 211 - 0038 - XX 6 SCREW,MACHINE:4- 40 X 0.312,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 46 441 - 1739 - XX 1 CHAS,CRV TRACER:BOTTOM 80009 4411739XX
(ATTACHING PARTS)
- 47 211 - 0541 - XX 2 SCREW,MACHINE:6- 32 X 0.25,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 48 390 - 0987 - XX 1 CABINET BOTTOM: 80009 3900987XX
(ATTACHING PARTS)
- 49 211 - 0007 - XX 6 SCREW,MACHINE:4- 40 X 0.188,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 50 390 - 1088 - XX 1 CABINET,TOP:ALUMINUM 80009 3901088XX
(ATTACHING PARTS)
- 51 211 - 0504 - XX 1 SCREW,MACHINE:6- 32 X 0.250,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 52 426 - 2136 - XX 1 FRAME SECT,CAB.:REAR,AL 80009 4262136XX

9-6 370B Service Manual

 Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
- 53 390 - 0985 - XX 1 CABINET SIDE:RIGHT 80009 3900985XX
(ATTACHING PARTS)
- 54 211 - 0504 - XX 1 SCREW,MACHINE:6- 32 X 0.250,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 55 333 - A428- 00 1 PANEL,REAR:370B,ALUMINUM 80009 3333717XX
(ATTACHING PARTS)
- 56 211 - 0507 - XX 6 SCREW,MACHINE:6- 32 X 0.312,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 57 343 - 1272 - XX 2 RTNR,CAB.COVER:BLUE,PLASTIC 80009 3431272XX
(ATTACHING PARTS)
- 58 213 - 0782 - XX 2 SCREW,TPG,TF:8- 32 X 0.625,FILH,STL 83486 ORDER BY DESC
(END ATTACHING PARTS)
- 59 -------- 1 MARKER,IDENT:MKD SERIAL NO
- 60 200 - 3300 - XX 1 GUARD,FAN: 80009 2003300XX
(ATTACHING PARTS)
- 61 129 - 1126 - XX 4 SPACER,POST:21.5MM L,4- 40,6- 32 THD,BRS 80009 129112600
(END ATTACHING PARTS)
- 62 378 - 0278 - XX 1 FILTER,AIR:125MM X 5MM THK TK0191 3780278XX
- 63 200 - 3277 - XX 1 COVER,FAN:ALUMINUM 80009 2003277XX
(ATTACHING PARTS)
- 64 211 - 0008 - XX 4 SCREW,MACHINE:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 65 343 - 1271 - XX 2 RTNR,CAB.COVER:BLUE,PLASTIC 80009 3431271XX
(ATTACHING PARTS)
- 66 213 - 0782 - XX 2 SCREW,TPG,TF:8- 32 X 0.625,FILH,STL 83486 ORDER BY DESC
(END ATTACHING PARTS)
- 67 119 - 2310 - 01 1 FAN,TUBEAXIAL:(B100) 80009 119231001
(ATTACHING PARTS)
- 68 210 - 0457 - XX 4 NUT,PL,ASSEM WA:6- 32 X 0.312,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 69 161 - 0257 - 01 1 CABLE ASSY,PWR:(W272 ) 80009 161025701
- 70 129 - A590- 00 2 SPACER,POST: 80009 129A59000
- 71 361 - 0704 - XX 4 SPACER,CKT BD:0.504 L X 0.188 HEX,BRS 80009 3610704XX
- 72 342 - A149- 00 1 INSULATOR,PLATE:CIRCUIT BOARD,PC 80009 3420894XX
- 73 671 - B127- 01 1 CKT BOARD ASSY:INTERFACE(A22 ) 80009 671B12700
(ATTACHING PARTS)
- 74 211 - 0871 - 00 4 SCR,ASSEM M3 X 6,PNH,STL TK0191 211087100
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 75 671 - B127- 01 2 CONN,RCPT,ELEC:(A22,J350&J450) 80009 671B12701
(ATTACHING PARTS of A22)
- 76 174 - 0295 - 00 1 CA ASSY,SP,ELEC:(A22W220) 80009 174029500
- 77 342 - 0782 - XX 1 INSULATOR,FILM:PRIMARY BOARD 80009 3420782XX

370B Service Manual 9-7

Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
- 78 670 - 9323 - 00 1 CKT BOARD ASSY:PRIMARY(A27 ) 80009 670932300
(ATTACHING PARTS)
- 79 211 - 0661 - XX 4 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 80 131 - 3666 - 00 1 CONN,RCPT,ELEC:CKTBD,2 PIN:(A27J272) 80009 131366600
- 81 131 - 3669 - 00 1 CONN,RCPT,ELEC:CKTBD,6 PIN:(A27J274) 80009 131366900
- 82 131 - 3667 - 00 1 CONN,RCPT,ELEC:CKTBD,3 PIN:(A27J270) 80009 131366700
- 83 119 - 3603 - 00 1 FILTER,RFI:115/230V,4A:(FL100) 80009 119360300
(ATTACHING PARTS)
- 84 211 - 0537 - XX 2 SCREW,MACHINE:6-32 X 0.375,TRH,STL TK0435 ORDER BY DESC
- 85 210 - 0407 - XX 2 NUT,PLAIN,HEX:6- 32 X 0.25,BRS 73743 3038 - 402
- 86 210 - 0006 - XX 2 WASHER,LOCK:#6INTL,0.018 THK,STL 78189 1206 - 00 - 00 - 0541
(END ATTACHING PARTS)
- 87 196 - 3112 - 01 1 LEAD,ELECTRICAL:18AWG,6.0 L,5- 4:(W17 ) 80009 196311201
- 88 210 - 0202 - XX 1 TERMINAL,LUG:0.146ID,LOCKING,BRZ TK1181 ORDER BY DESC
(ATTACHING PARTS)
- 89 211 - 0565 - XX 1 SCREW,MACHINE:6- 32 X 0.250,TRH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 90 196 - 3098 - 01 1 LEAD,ELECTRICAL:18AWG,7.0 L,5- 4:(W19 ) 80009 196390800
- 91 210 - 0202 - XX 1 TERMINAL,LUG:0.146ID,LOCKING,BRZ TK1181 ORDER BY DESC
(ATTACHING PARTS)
- 92 211 - 0565 - XX 1 SCREW,MACHINE:6- 32 X 0.250,TRH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 93 210 - 0202 - XX 1 TERMINAL,LUG:0.146ID,LOCKING,BRZ TK1181 ORDER BY DESC
(ATTACHING PARTS)
- 94 210 - 0407 - XX 1 NUT,PLAIN,HEX:6- 32 X 0.25,BRS 73743 3038 - 402
(END ATTACHING PARTS)
- 95 220 - A178- 00 1 NUT,PLATE, 80009 220A17800

9-8 370B Service Manual

 70

95

Figure 9- 1: Cabinet, Rear

370B Service Manual 9- 9

 81
Figure 9- 2: Display, Front

9- 10 370B Service Manual

 Mechanical Parts List

Replaceable mechanical parts list

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
2-1 200 - 3281 - XX 1 COVER,BEZEL:POLYCARBONATE,TEK TAN 80009 2003281XX
-2 200 - 3276 - XX 1 BEZEL,CRT:PC,TEK TAN 80009 2003276XX
(ATTACHING PARTS)
-3 211 - 0538 - XX 2 SCREW,MACHINE:6- 32 X 0.312,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
-4 378 - 0276 - XX 1 FILTER,LT,CRT:BLUE,108.4MMX 134.4MM X 1MM 80009 3780276XX
-5 361 - 1381 - XX 1 SPACER,RING:CRT,0.4MM 80009 3611381XX
-6 337 - 3328 - XX 1 SHIELD,CRT:CLEAR 80009 3373328XX
-7 426 - 2133 - XX 1 FRAME,CRT: 80009 4262133XX
(ATTACHING PARTS)
-8 211 - 0512 - XX 4 SCREW,MACHINE:6- 32 X 0.5,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
-9 343 - 1269 - XX 2 RETAINER,CRT:FRONT,(A) 80009 3431269XX
(ATTACHING PARTS)
- 10 212 - 0022 - XX 2 SCREW,MACHINE:8- 32 X 1.5,PNH,STL TK0435 2011 - 300
(END ATTACHING PARTS)
- 11 343 - 1270 - XX 2 RETAINER,CRT:FRONT,(B) 80009 3431270XX
(ATTACHING PARTS)
- 12 212 - 0022 - XX 2 SCREW,MACHINE:8- 32 X 1.5,PNH,STL TK0435 2011 - 300
(END ATTACHING PARTS)
- 13 331 - 0491 - XX 1 MASK,CRT: 80009 3310491XX
- 14 174 - 0313 - 00 1 CA ASSY,SP,ELEC:2,26AWG,30.0 L,RIBBON:(W280) 80009 174031300
- 15 174 - 0312 - 00 1 CA ASSY,SP,ELEC:2,26AWG,22.0 L,RIBBON:(W290) 80009 174031200
- 16 670 - 9324 - XX 2 CKT BOARD ASSY:LAMP(A28& A29 )
(ATTACHING PARTS)
- 17 211 - 0062 - XX 4 SCREW,MACHINE:2- 56 X 0.312,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 18 343 - 1268 - XX 2 RETAINER,LIGHT:REFLECTOR 80009 3431268XX
- 19 378 - 0614 - XX 2 REFLECTOR,LIGHT:INT SCALE ILLUMINATION 0JR05 ORDER BY DESC
- 20 214 - 3886 - XX 2 SPRING,RTNR:SCALE LAMP 80009 2143886XX
- 21 1 ELECTRON TUBE:(V100 )
- 22 253 - 0267 - XX 1 TAPE,PRESS SENS:0.08 X 20 X 20000MM,AL FOIL 80009 2530267XX
- 23 253 - 0137 - XX 1 TAPE,SILICONE:REDRBR,1.25 X 0.02 99742 2650
- 24 426 - A191- 00 1 FRAME,FRONT: 80009 4262333XX
(ATTACHING PARTS)
- 25 211 - 0538 - XX 8 SCREW,MACHINE:6-32 X 0.312,FLH,STL TK0435 ORDER BY DESC
- 26 211 - 0541 - XX 2 SCREW,MACHINE:6- 32 X 0.25,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 27 214 - 3880 - XX 1 CONTACT,SPRING:GROUNDING CRT 80009 2143880XX
(ATTACHING PARTS)
- 28 211 - 0661 - XX 1 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)

370B Service Manual 9-11

Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
- 29 255 - 1106 - XX 1 PLASTIC CHANNEL:250 X 3.3 X 4.0MM,NYLON 80009 2551106XX
- 30 334 - 6691 - XX 1 MARKER,IDENT:MKD DANGER 80009 3346691XX
- 31 334 - 6805 - XX 1 MARKER,IDENT:MKD WARNING 80009 3346805XX
- 32 337 - 3325 - XX 1 SHIELD,CRT: 80009 3373325XX
(ATTACHING PARTS)
- 33 211 - 0661 - XX 4 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 34 108 - 1345 - 02 1 COIL,TUBE DEFL:TRACE ROTATOR:(L100 ) 80009 108134502
(ATTACHING PARTS)
- 35 211 - 0661 - XX 2 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 36 129 - 1123 - XX 2 SPACER,POST:33MM L,4- 40 THD,BRASS 80009 1291123XX
(ATTACHING PARTS)
- 37 211 - 0661 - XX 2 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 38 348 - 0948 - XX 1 GROMMET,PLASTIC:BLACK,RING,9.5MMID 80009 3480948XX
- 39 108 - 1347 - 01 1 COIL,TUBE DEFL:Y- AXIS ALIGNMENT:(L120 ) 80009 108134701
(ATTACHING PARTS)
- 40 211 - 0661 - XX 2 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 41 354 - 0347 - XX 1 RING,CRT CLAMP:2.127ID X 2.595 OD X 0.563 0JR05 ORDER BY DESC
(ATTACHING PARTS)
- 42 211 - 0170 - XX 2 SCREW,MACHINE:4-40 X 2.25,PNH,SST TK0435 ORDER BY DESC
- 43 214 - 1333 - XX 2 SPRING,HLCPS:0.213 OD X 0.375,CLE,CU- BE 8X345 ORDER BY DESC
(END ATTACHING PARTS)
- 44 343 - 0205 - XX 1 RTNR,ELCTRN TU:3.0 DIA X 1.5 L,DELRIN 80009 3430205XX
(ATTACHING PARTS)
- 45 211 - 0578 - XX 4 SCREW,MACHINE:6-32 X 0.438,PNH,STL TK0435 ORDER BY DESC
- 46 210 - 0949 - XX 4 WASHER,FLAT:0.141 ID X 0.5 OD X 0.062,BRS 12327 ORDER BY DESC
(END ATTACHING PARTS)
- 47 196 - 3099 - 00 1 LEAD,ELECTRICAL:24AWG,10.0 L:(W14 ) 80009 196309900
- 48 119 - 2162 - 01 1 HV MODULER: 2kV INPUT,12kV OUTPUT 80009 119216201
- 49 366 - 0625 - XX 5 KNOB:SILVER GRAY,9.5MM OD 80009 3660625XX
- 50 358 - 0378 - XX 3 BUSHING,SLEEVE:0.131ID X 0.18 OD X 0.125L 80009 3580378XX
- 51 366 - 0620 - XX 3 KNOB:SILVER GRAY,25MM OD 80009 3660620XX
- 52 333 - A429- 00 1 PANEL,FRONT:370B 80009 3333715XX
- 53 210 - 0586 - XX 2 NUT,PL,ASSEM WA:4- 40 X 0.25,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 54 378 - 0349 - XX 1 FILTER,LED DSPL:GRAY,10.8 & 18.3M,PC 80009 3780349XX
- 55 378 - 0277 - XX 1 FILTER,LT,CRT:SMOKE GRAY 80009 3780277XX
- 56 351 - 0853 - XX 1 GUIDE,PB:370BMAIN KEY BD,PC 80009 3510853XX

9-12 370B Service Manual

 Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
- 57 671 - 1149 - 02 1 CIRCUIT BD ASSY:SUB KEY(A12)
(ATTACHING PARTS)
- 58 129 - 1131 - XX 6 SPACER,POST:12.7MM L,4- 40 THD,BRASS 80009 1291131XX
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 59 129 - 1128 - XX 54 .SPACER,POST:5.1MM,L,POLYCARBONATE 80009 1291128XX
- 60 131 - 3677 - XX 8 .CONN,RCPT,ELEC:1 X 5 FEMALE 80009 1313677XX
- 61 260 - 2156 - 00 38 SWITCH,KEY:(A12S300,S301,S302,S303,S304,S305, 80009 260215600
S310,S311,S312,S313,S314,S315,S320,S321,S322,S323,
S324,S325,S330,S331,S332,S333,S335,S350,S351,S353,
S354,S355,S360,S361,S362,S363,S364,S365,S370,S371,
S372,S373 )
- 62 366 - 0617 - XX 44 PUSH BUTTON:SILVER GRAY,9.6 X 4.2 X 8.5MM 80009 3660617XX
- 63 671 - B235- 00 1 CKT BOARD ASSY:MAIN KEY(A11) 80009 671B23500
(ATTACHING PARTS)
- 64 211 - 0661 - XX 6 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 65 407 - 3474 - XX 1 .BRACKET,ANGLE:VAR RES MTG 80009 4073474XX
- 66 311 - 2457 - 00 5 RES,VAR,NONWW:PNL,10K 80009 311245700
OHM,1/2W,20%:(A11R302,R312,R322,R330,R340)
(ATTACHING PARTS)
- 67 210 - 0583 - XX 5 .NUT,PLAIN,HEX:0.25- 32 X 0.312,BRS 73743 2X - 20319 - 402
- 68 210 - 0046 - XX 4 .WASHER,LOCK:0.261ID,INTL,0.018 THK,STL 78189 1214 - 05 - 00 - 0541
(END ATTACHING PARTS)
- 69 407 - 3475 - XX 1 .BRACKET,ANGLE:VAR RES MTG,W/CUT LEAD 80009 4073475XX
- 70 311 - 2456 - 00 3 RES,VAR,NONWW:PNL,10KOHM,1/2W,20%: 80009 311245600
(A11R350,R360,R370 )
(ATTACHING PARTS)
- 71 210 - 0583 - XX 3 .NUT,PLAIN,HEX:0.25- 32 X 0.312,BRS 73743 2X - 20319 - 402
- 72 210 - 0046 - XX 2 .WASHER,LOCK:0.261ID,INTL,0.018 THK,STL 78189 1214 - 05 - 00 - 0541
(END ATTACHING PARTS)
- 73 210 - 0223 - XX 2 .TERMINAL,LUG:0.26ID,LOCKING,BRZ 0KB01 210 - 0223 - XX
- 74 196 - 3096 - 00 1 LEAD,ELECTRICAL:18AWG,3.5 L,5- 4:(A11W111) 80009 196309600
- 75 196 - 3096 - 00 1 LEAD,ELECTRICAL:18AWG,3.5 L,5- 4:(A11W112) 80009 196309600
- 76 174 - 0293 - 00 1 CA ASSY,SP,ELEC:40,28 AWG,4.3L,RIBBON:(A11W110) 80009 174029300
- 77 210 - 0201 - XX 1 .TERMINAL,LUG:0.12ID,LOCKING,BRZ TK1741 2004 - 4 PHOSPHOR
- 78 211 - 0008 - XX 1 SCREW,MACHINE:4-40 X 0.25,PNH,STL TK0435 ORDER BY DESC
- 79 407 - 3851 - XX 1 BRACKET,ANGLE:FRONTPANEL MTG,AL 80009 4073851XX
(ATTACHING PARTS)
- 80 211 - 0106 - XX 2 SCREW,MACHINE:4- 40 X 0.625,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 81 386 - A842- 00 1 SUB PANEL 80009 386A84200

370B Service Manual 9-13

Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
3-1 441 - 1740 - XX 1 CHASSIS,CKT BD:370B,ALUMINUM TK0191 4411740XX
-2 255 - 0334 - XX 1 PLASTIC CHANNEL:12.75X 0.175 X 0.155,NYLON 11897 122 - NN - 2500 - 060
-3 343 - 0778 - XX 2 CLAMP,CABLE:5MMID,NYLON 80009 3430778XX
-4 348 - 0948 - XX 1 GROMMET,PLASTIC:BLACK,RING,9.5MMID 80009 3480948XX
-5 351 - 0769 - XX 2 GUIDE,CKT BD: 80009 3510769XX
-6 343 - 1289 - XX 1 CLAMP,CABLE:STEEL 80009 3431289XX
-7 343 - 1084 - XX 3 CLAMP,CABLE:NYLON 80009 3431084XX
-8 255 - 1107 - XX 1 PLASTIC CHANNEL:500 X 3.7 X 4.0MM,NYLON 80009 2551107XX
-9 255 - 0334 - XX 1 PLASTIC CHANNEL:12.75X 0.175 X 0.155,NYLON 11897 122 - NN - 2500 - 060
- 10 255 - 0334 - XX 1 PLASTIC CHANNEL:12.75X 0.175 X 0.155,NYLON 11897 122 - NN - 2500 - 060
- 11 670 - 9309 - 09 1 CKT BOARD ASSY:STEP GEN(A7) 80009 670930909
(ATTACHING PARTS)
- 12 211 - 0661 - XX 3 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 17 211 - 0315 - XX 1 .SCR,ASSEM WSHR:4- 40 X 0.437,PHN,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 21 156 - 0446 - 00 1 MICROCKT,DGTL:3- TERM POSI VOL REG +12V:(A7U170 ) 80009 156044600
- 22 214 - 4003 - XX 1 .HEAT SINK,XSTR:TO - 220,AL 80009 2144003XX
(ATTACHING PARTS)
- 23 211 - 0661 - XX 1 .SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
- 24 210 - 0586 - XX 1 .NUT,PL,ASSEM WA:4- 40 X 0.25,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 26 174 - 0310 - 00 1 CA ASSY,SP,ELEC,10,22 AWG18.0 RIBBON:(W72) 80009 174031000
- 27 671 - 0236 - 02 1 CIRCUIT BD ASSY:MOTHER,(A1) 80009 671023602
(ATTACHING PARTS)
- 28 211 - 0661 - XX 8 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 39 407 - 3479 - XX 1 BRACKET,CKT BD:ALUMINUM 80009 4073479XX
(ATTACHING PARTS)
- 40 211 - 0507 - XX 2 SCREW,MACHINE:6- 32 X 0.312,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 41 670 - 9320 - 01 1 CKT BOARD ASSY:LV SUPPLY,(A19) 80009 670932001
(ATTACHING PARTS)
- 42 211 - 0661 - XX 3 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
- 43 211 - 0507 - XX 3 SCREW,MACHINE:6- 32 X 0.312,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 44 214 - 3874 - XX 1 .HT SK,PWR SPLY:LV,AL 80009 2143874XX
(ATTACHING PARTS)
- 45 211 - 0661 - XX 3 .SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)

9-14 370B Service Manual

 Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
- 46 151 - 0561 - 00 2 TRANSISTOR:PNP,SI,PWR:(Q230,Q600 ) 80009 151056200
(ATTACHING PARTS)
151 - 0562 - 00 1 TRANSISTOR:PNP,SI,PWR:(A19Q130) 80009 151056200
(ATTACHING PARTS)
- 47 211 - 0244 - XX 3 .SCR,ASSEM WSHR:4- 40 X 0.312,PNH,STL TK0435 7772 - 312
(END ATTACHING PARTS)
- 48 156 - 2830 - 00 1 MICROCKT,LINEAR:VOLTAGE REG,+12V:(A19U310) 80009 156283000
(ATTACHING PARTS)
156 - 2831 - 00 1 MICROCKT,LINEAR:VOLTAGE REG,+5V,STR:(A19U100), 80009 156283100
(ATTACHING PARTS)
- 49 211 - 0315 - XX 4 .SCR,ASSEM WSHR:4- 40 X 0.437,PHN,STL TK0435 ORDER BY DESC
- 50 342 - 0790- XX 2 .INSULATOR,FILM:MICA,0.07MA 80009 3420790XX
(END ATTACHING PARTS)
- 51 152 - 1119 - 00 2 SEMICOND DVC,DI:RECT,SI,100V,10A:(A19CR100,CR300) 80009 152111900
(ATTACHING PARTS)
152 - 1120 - 00 2 SEMICOND DVC,DI:RECT,SI,100V,10A:(A19CR200,CR400, 80009 152112000
U410)
(ATTACHING PARTS)
- 52 211 - 0244 - XX 5 .SCR,ASSEM WSHR:4- 40 X 0.312,PNH,STL TK0435 7772 - 312
(END ATTACHING PARTS)
- 53 148 - 1010 - 00 1 RELAY,SOL STATE:5A,250VAC:(A19U700) 80009 148101000
(ATTACHING PARTS)
- 54 211 - 0244 - XX 2 .SCR,ASSEM WSHR:4- 40 X 0.312,PNH,STL TK0435 7772 - 312
(END ATTACHING PARTS)
- 55 131 - 3668 - 00 2 CONN,RCPT,ELEC:CKTBD,4 PIN:(A19J64,J190) 80009 131366800
- 56 131 - 3671 - 00 1 CONN,RCPT,ELEC:CKTBD,15 PIN:(A19J196) 80009 131367100
- 57 131 - 0589 - 00 3 TERMINAL,PIN:PRESSFIT/PCB,;MALE,STR:(A19J72,J194, 22526 48283 - 087
J198)
- 58 131 - 0608 - 00 2 CONN,TERMINAL:PRESSFIT/PCB,;MALE,STR:(A19J280,J290) 22526 48283 - 018
- 59 174 - 0328 - 00 1 CA ASSY,SP,ELEC:4,18 AWG,15.5 L:( W190) 80009 174032800
- 60 174 - 0308 - 00 1 CA ASSY,SP,ELEC:( W194) 80009 174030800
- 61 348 - 1048 - XX 2 PAD,CUSHIONING:150MM X 12MM X 13MM TK0191 3481048XX
- 62 343 - 1273 - XX 2 RETAINER,CKT BD:BRASS 80009 3431273XX
(ATTACHING PARTS)
- 63 211 - 0504 - XX 2 SCREW,MACHINE:6- 32 X 0.250,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 64 671 - B126- 01 1 CKT BOARD ASSY:CPU( A2 ) 80009 671B12601
- 69 105 - 0899 - XX .301393 .301782 2 .EJECTOR,CKT BD:NYLON 80009 1050899XX
105 - 0978 - XX .301783 2 .EJECTOR,CKT BD:NYLON TK00Z 21 - 0608
- 70 337 - 3326 - XX .301393 .302428 1 .SHIELD,ELEC:CPUBD 80009 3373326XX
(ATTACHING PARTS)
- 71 211 - 0661 - XX .301393 .302428 5 .SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 72 671 - B213- 00 1 CKT BOARD ASSY:A/D( A3 ) 80009 671B21300

370B Service Manual 9-15

Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
- 73 131 - 3650 - 00 1 CONN,PLUG,ELEC:CKTBD,RTANG,2 X 32,0.1 SP:( A3P30 ) 80009 131365000
- 79 337 - 3326- XX 1 .SHIELD,ELEC:CPUBD 80009 3373326XX
(ATTACHING PARTS)
- 80 211 - 0661 - XX .301393 .302428 5 .SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 81 670 - 9306 - 04 1 CKT BOARD ASSY:DGTL DISPLAY( A4 ) 80009 670930604
- 85 105 - 0899 - XX .301393 .301782 2 .EJECTOR,CKT BD:NYLON 80009 1050899XX
105 - 0978 - XX .301783 2 .EJECTOR,CKT BD:NYLON TK00Z 21 - 0608
- 86 337 - 3326- XX 1 .SHIELD,ELEC:CPUBD 80009 3373326XX
(ATTACHING PARTS)
- 87 211 - 0661 - XX 5 .SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 88 670 - 9307 - 05 1 CKT BOARD ASSY:DISPLAY CONT( A5 ) 80009 670930705
- 93 337 - 3326 - XX .301393 .302428 1 .SHIELD,ELEC:CPUBD 80009 3373326XX
(ATTACHING PARTS)
- 94 211 - 0661 - XX .301393 .302428 5 .SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)

9-16 370B Service Manual

 Figure 9- 3: Chassis Circuit Boards

370B Service Manual 9- 17

Figure 9- 4: Power Supply

9- 18 370B Service Manual

 Mechanical Parts List

Replaceable mechanical parts list

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
4-1 670 - 9308 - 06 1 CKT BOARD ASSY:COLLSPLY OUT( A6 ) 80009 670930806
(ATTACHING PARTS)
-2 211 - 0507 - XX 2 SCREW,MACHINE:6- 32 X 0.312,PNH,STL TK0435 ORDER BY DESC
-3 211 - 0661 - XX 2 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
-4 151 - 1201 - 00 2 TRANSISTOR:PMOS,FET,PWR,200V:(A6Q438,Q440) 80009 151120100
151 - 1202 - 00 2 ( A6Q538,Q540 ) 80009 151120200
(ATTACHING PARTS)
-5 211 - 0315 - XX 4 .SCR,ASSEM WSHR:4- 40 X 0.437,PHN,STL TK0435 ORDER BY DESC
-6 342 - 0787 - XX 4 .INSULATOR,PLATE:XSTR,TO - 3P,SI RUBBER 80009 3420787XX
(END ATTACHING PARTS)
-7 174 - 0304 - 00 1 CA ASSY,SP,ELEC:2,26 AWG,6.0 L,RIBBON: 80009 174030400
( A6W66 )
-8 260 - 2332 - 01 1 SWITCH,THERMOSTATIC:NC,OPEN 70 DEG C,3A,250V: TK0191 260233201
( A6S92 ) (ATTACHING PARTS)
-9 211 - 0661 - XX 2 .SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 10 174 - 0301 - 00 1 CA ASSY,SP,ELEC:4,22 AWG,16.0 L:( A6W64 ) 80009 174030100
- 11 131 - 3672 - 00 1 CONN,RCPT,ELEC:HEADER,16PIN:( A6J60 ) 80009 131367200
- 12 131 - 0608 - 00 1 CONN,TERMINAL:PRESSFIT/PCB,;MALE,STR: 22526 48283 - 018
( A6J66 )
- 13 131 - 0589 - 00 1 TERMINAL,PIN:PRESSFIT/PCB,;MALE,STR:(A6J62 ) 22526 48283 - 087
- 14 407 - 3470 - XX 1 BRACKET,CKT BD:COLLECTOR SUPPLY OUTPUT 80009 4073470XX
- 15 343 - 1084 - XX 2 CLAMP,CABLE:NYLON 80009 3431084XX
- 16 337 - 3330 - XX .301393 .302394 1 SHIELD,ELEC:COLLECTOR SUPPLY 80009 3373330XX
(ATTACHING PARTS)
- 17 211 - 0008 - XX .301393 .302394 4 SCREW,MACHINE:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 18 334 - 6695 - XX 301393 .302394 1 MARKER,IDENT:MKD DANGER & POT 80009 3346695XX
- 19 407 - 3478 - XX 1 BRACKET,XFMR:LEFT,ALUMINUM 80009 4073478XX
(ATTACHING PARTS)
- 20 212 - 0507 - XX 2 SCREW,MACHINE:10- 32 X 0.375,PNH,STL TK0435 MACHINE SCREW
(END ATTACHING PARTS)
- 21 407 - 3907 - XX 1 BRACKET,XFMR:RIGHT,ALUMINUM 80009 4073907XX
(ATTACHING PARTS)
- 22 212 - 0507 - XX 2 SCREW,MACHINE:10- 32 X 0.375,PNH,STL TK0435 MACHINE SCREW
(END ATTACHING PARTS)
- 23 214 - 3974 - XX 1 HEAT SINK,ELEC:TRANSFORMER,ALUMINUM 80009 2143974XX
(ATTACHING PARTS)
- 24 211 - 0538 - XX 2 SCREW,MACHINE:6- 32 X 0.312,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 25 120 - 1678 - 01 1 XFMR,PWR,STU:100- 120VAC IN,48- 66HZ:( T100 ) 80009 120167801
(ATTACHING PARTS)

370B Service Manual 9-19

Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
- 26 212 - 0507 - XX 8 SCREW,MACHINE:10- 32 X 0.375,PNH,STL TK0435 MACHINE SCREW
- 27 210 - 1003 - XX 8 WASHER,FLAT:0.2 ID X 0.438 OD X 0.036 BRS 12327 ORDER BY DESC
(END ATTACHING PARTS)
- 28 260 - 2323 - 00 1 SWITCH,PUSH:DPST,15A,250V,ON/OFF:( S100 ) 80009 260232300
(ATTACHING PARTS)
- 29 211 - 0751 - XX 2 SCR,ASSEM WSHR:M3 X 8 80009 2110751XX
(END ATTACHING PARTS)
- 30 174 - 0327 - 00 1 CA ASSY,SP,ELEC:2,18 AWG,7.0 L:( W270 ) 80009 174032700
- 31 196 - 3110 - 00 1 LEAD,ELECTRICAL:18AWG,7.0 L,8- 0:( W16 ) 80009 196311000
- 32 196 - 3111 - 00 1 LEAD,ELECTRICAL:18AWG,7.0 L,8- 9:( W18 ) 80009 196311100
- 33 386 - 5485 - XX 1 PLATE,CONN MTG:FEMALE,STEEL 80009 3865485XX
(ATTACHING PARTS)
- 34 211 - 0507 - XX 2 SCREW,MACHINE:6- 32 X 0.312,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 35 174 - 0296 - 00 1 CA ASSY,SP,ELEC:34,28 AWG,5.5 L,RIBBON:(W400 ) 80009 174029600
(ATTACHING PARTS)
- 36 211 - 0661 - XX 2 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 37 198 - 5714 - 00 1 WIRE SET,ELEC:370B,W/D- SUB CONN:( W490 ) 80009 198571400
(ATTACHING PARTS)
- 38 211 - 0661 - XX 2 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 39 386 - 5909 - XX 1 PLATE,CONN MTG:FEMALE,STEEL 80009 3865909XX
(ATTACHING PARTS)
- 40 211 - 0507 - XX 2 SCREW,MACHINE:6- 32 X 0.312,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 41 441 - 1948 - XX 1 CHAS ASSY,CURV:TRCR,REAR,AL 80009 4411948XX
(ATTACHING PARTS)
- 42 211 - 0507 - XX 4 SCREW,MACHINE:6- 32 X 0.312,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 43 441 - 1743 - XX 1 CHASSIS,CRT:LEFT 80009 4411743XX
(ATTACHING PARTS)
- 44 211 - 0504 - XX 3 SCREW,MACHINE:6- 32 X 0.250,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 45 670 - 9319 - 02 1 CKT BOARD ASSY:CRT OUTPUT( A18 ) 80009 670931902
(ATTACHING PARTS)
- 46 129 - 1139 - XX 4 SPACER,POST:25MM L,W4- 40 THD,BRASS 80009 1291139XX
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 47 131 - 0608 - 00 1 CONN,TERMINAL:PRESSFIT/PCB,;MALE,STR:(A18J180) 22526 48283 - 018
TERMINAL,PIN:PRESSFIT/PCB,;MALE,STR
131 - 0589 - 00 3 (A18J182,J184,J186) 22526 48283 - 087
- 48 342 - 0785 - XX 1 INSULATOR,PLATE:CRT OUTPUT 80009 3420785XX
(ATTACHING PARTS)

9-20 370B Service Manual

 Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
- 49 211 - 0661 - XX 4 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 50 343 - 1288 - XX 1 CLAMP,CABLE:PLASTIC 80009 3431288XX
- 51 174 - 0309 - 00 1 CA ASSY,SP,ELEC:10,22 AWG,5.0 L,RIBBON:(W182 ) 80009 174030900
- 52 174 - 0314 - 00 1 CA ASSY,SP,ELEC:9,26 AWG,7.5 L,RIBBON:(W180 ) 80009 174031400
- 53 670 - B211 - 00 1 CKT BOARD ASSY:HV REG( A20 ) 80009 670B21100
(ATTACHING PARTS)
- 54 211 - 0661 - XX 4 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 55 119 - 2162 - 01 1 HV MODULE:( A20U300 ) 80009 119216201
(ATTACHING PARTS)
- 56 211 - 0012 - XX 2 .SCREW,MACHINE:4-40 X 0.375,PNH,STL TK0435 ORDER BY DESC
- 57 210 - 0586 - XX 2 .NUT,PL,ASSEM WA:4- 40 X 0.25,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 58 214 - 0579 - 00 3 TERM,TEST POINT:PCB,TEST POINT;EYELET: 0J260 ORDER BY DESC
( A20TP200,TP300,TP400 )
- 59 131 - 0589 - 00 3 TERMINAL,PIN:PRESSFIT/PCB,;MALE,STR: 22526 48283 - 087
( A20J182,J194,J200)
- 60 343 - 1275 - XX 1 RETAINER,XSTR:HV,SST 80009 3431275XX
(ATTACHING PARTS)
- 61 211 - 0661 - XX 1 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 62 337 - 3329 - XX 1 SHIELD,ELEC:HVREG 80009 3373329XX
(ATTACHING PARTS)
- 63 211 - 0008 - XX 4 SCREW,MACHINE:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 64 334 - 6694 - XX 1 MARKER,IDENT:MKD DANGER & POT 80009 3346694XX

370B Service Manual 9-21

Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
5-1 333 - 3514 - XX 1 PANEL,FRONT:371,PWR SW 80009 3333514XX
(ATTACHING PARTS)
-2 200 - 0103 - XX 1 NUT,PLAIN,KNURL:0.25- 28 X 0.375 INCH OD,BRS TK0588 ORDER BY DESC
-3 355 - 0507 - XX 1 STUD,SHOULDERED:BINDINGPOST,BRS TK0588 ORDER BY DESC
-4 210 - 0455 - XX 1 NUT,PLAIN,HEX:0.25- 28 X 0.375,BRS 73743 3089 - 402
-5 210 - 0046 - XX 1 WASHER,LOCK:0.261ID,INTL,0.018 THK,STL 78189 1214 - 05 - 00 - 0541
(END ATTACHING PARTS)
-6 344 - 0396 - XX 1 CLIP,CABLE:PVC 80009 3440396XX
-7 426 - 2334 - XX 1 SUBPANEL,TEST F: 80009 4262334XX
-8 333 - 3718 - XX 1 PANEL,FRONT 80009 3333718XX
-9 407 - 3472 - XX 1 BRACKET,ANGLE:LOWER,PANEL 80009 4073472XX
(ATTACHING PARTS)
- 10 210 - 0586 - XX 2 NUT,PL,ASSEM WA:4- 40 X 0.25,STL TK0435 ORDER BY DESC
- 11 211 - 0038 - XX 2 SCREW,MACHINE:4- 40 X 0.312,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 12 122 - 0183 - XX 1 ANGLE,RAIL:SUBPANEL MTG,LEFT 80009 1220183XX
(ATTACHING PARTS)
- 13 210 - 0586 - XX 1 NUT,PL,ASSEM WA:4- 40 X 0.25,STL TK0435 ORDER BY DESC
- 14 211 - 0038 - XX 5 SCREW,MACHINE:4- 40 X 0.312,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 15 351 - 0854 - XX 1 GUIDE,PB:370BVAR COIL SUPPLY BD,PC 80009 3510854XX
(ATTACHING PARTS)
- 16 210 - 0586 - XX 2 NUT,PL,ASSEM WA:4- 40 X 0.25,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 17 311 - 2457 - 00 1 RES,VAR,NONWW:PNL,10KOHM,1/2W,20%:( R210 ) 80009 311245700
(ATTACHING PARTS)
- 18 210 - 0583 - XX 1 NUT,PLAIN,HEX:0.25- 32 X 0.312,BRS 73743 2X - 20319 - 402
- 19 210 - 0046 - XX 1 WASHER,LOCK:0.261ID,INTL,0.018 THK,STL 78189 1214 - 05 - 00 - 0541
(END ATTACHING PARTS)
- 20 366 - 0626 - XX 1 KNOB:SILVER GRAY,12MM OD 80009 3660626XX
- 21 198 - 5686 - 00 1 WIRE SET,ELEC:( W210 ) 80009 198568600
- 22 260 - 2497 - 03 1 SWITCH,ROTARY:ENCODER:(S200) 80009 260249703
(ATTACHING PARTS)
- 23 210 - 0207 - XX 1 TERMINAL,LUG:0.385OD,PLAIN,BRS 12697 01136902
(END ATTACHING PARTS)
- 24 366 - 0621 - XX 1 SHELL,KNOB:TEKTAN,30MM OD X 15MM H,ABS 80009 3660621XX
- 25 377 - 0609 - XX 1 INSERT,KNOB:8.6MMID X 16MM OD X 8MM H,AL 80009 3770609XX
(ATTACHING PARTS)
- 26 213 - 0022 - XX 1 SETSCREW:4- 40 X 0.188,STL 0KB01 ORDER BY DESC
(END ATTACHING PARTS)
- 27 671 - B245- 00 1 CKT BOARD ASSY:CONFIG.LED( A15 ) 80009 671B24500
(ATTACHING PARTS)

9-22 370B Service Manual

 Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
- 28 210 - 0586 - XX 2 NUT,PL,ASSEM WA:4- 40 X 0.25,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 29 129 - 1128 - XX 6 .SPACER,POST:5.1MM,L,POLYCARBONATE 80009 1291128XX
- 30 131 - 0589 - 00 2 TTERMINAL,PIN:PRESSFIT/PCB,;MALE,STR: 22526 48283 - 087
( A15J200,J210)
- 31 174 - 1775 - 01 1 CA ASSY,SP,ELEC:16,28 AWG,250MM L,RIBBON: 80009 174177501
( A15W150 )
- 32 366 - 0617 - XX 2 PUSH BUTTON:SILVER GRAY,9.6 X 4.2 X 8.5MM 80009 3660617XX
- 33 386 - 5395 - XX 1 PLATE,MTG ASSY:TEST ADAPTER 80009 3865395XX
(ATTACHING PARTS)
- 34 211 - 0025 - XX 4 SCREW,MACHINE:4- 40 X 0.375,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 35 386 - 5919 - XX 1 PLATE,ELEC:GND,ALUMINUM 80009 3865919XX
- 36 348 - 0970 - XX 2 SHLD GSKT,ELEK:FINGERTYPE,0.75 L 80009 3480970XX
- 37 210 - 0269 - XX 1 TERMINAL,LUG:0.257ID,PLAIN,BRSTINNED 0KB01 905 - 020
- 38 343 - 1367 - XX 3 CLAMP,LOOP:3.3MM ID,NYLON TK0AR 30 - 0608
(ATTACHING PARTS)
- 39 210 - 0407 - XX 3 NUT,PLAIN,HEX:6- 32 X 0.25,BRS 73743 3038 - 402
(END ATTACHING PARTS)
- 40 343 - 1286 - XX 1 CLAMP,CABLE:6.8ID,NYLON 80009 3431286XX
(ATTACHING PARTS)
- 41 210 - 0407 - XX 1 NUT,PLAIN,HEX:6- 32 X 0.25,BRS 73743 3038 - 402
(END ATTACHING PARTS)
- 42 136 - 0887 - XX 4 SOCKET,PIN TERM:0.16 DIA,RED 80009 1360887XX
- 43 136 - 0888 - XX 11 SOCKET,PIN TERM:0.16 DIA,GRAY 80009 1360888XX
- 44 210 - 0241 - XX 2 TERMINAL,LUG:0.515ID,PLAIN,STL TK1665 ORDER BY DESC
- 45 198 - 5680 - 01 1 WIRE SET,ELEC:( W91 ) 80009 198569600
- 46 198 - 5680 - 00 1 WIRE SET,ELEC:( W95 ) 80009 198568000
- 47 198 - 5683 - 00 1 WIRE SET,ELEC::(W3 ) 80009 198568300
- 48 198 - 5700 - 00 1 WIRE SET,ELEC:( W4 ) 80009 198570000
- 49 198 - 5681 - 01 1 WIRE SET,ELEC:( W104 ) 80009 198568101
- 50 198 - 5682 - 00 1 WIRE SET,ELEC:( W103 ) 80009 198568200
- 51 198 - 5679 - 00 1 WIRE SET,ELEC:( W102 ) 80009 198567900
- 52 343 - 0549 - XX 4 STRAP,TIEDOWN,E:0.098 W X 4.0 L,ZYTEL TK1499 HW - 047
- 53 407 - 3889 - XX 1 BRACKET,MTG:ADAPTERPL W/PRESSNUT,AL 80009 4073889XX
(ATTACHING PARTS)
- 54 211 - 0038 - XX 4 SCREW,MACHINE:4- 40 X 0.312,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 55 407 - 3484 - XX 2 BRACKET,SW MTG:ALUMINUM 80009 4073484XX
(ATTACHING PARTS)

370B Service Manual 9-23

Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
- 56 211 - 0038 - XX 4 SCREW,MACHINE:4- 40 X 0.312,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 57 260 - 2324- 00 2 SWITCH,SENS:( S400,S402 ) 80009 260232400
(ATTACHING PARTS)
- 58 213 - 0986 - XX 4 SCREW,MACHINE:2- 26 X 12MM,HEX,BRS 80009 2130986XX
- 59 210 - 0938 - XX 4 WASHER,FLAT:0.109 ID X 0.25 OD X 0.032,STL TK0413 ORDER BY DESC
- 60 210 - 0054 - XX 4 WASHER,LOCK:#4SPLIT,0.025 THK STL 86928 ORDER BY DESC
(END ATTACHING PARTS)
- 61 198 - 5685 - 00 1 WIRE SET,ELEC:( W401 ) 80009 198568500
- 62 196 - 3270 - 00 1 LEAD,ELECTRICAL:26AWG,28.0 L,N- 0( W402 ) 80009 196327000
- 63 343 - 0549 - XX 3 STRAP,TIEDOWN,E:0.098 W X 4.0 L,ZYTEL TK1499 HW - 047
- 64 344 - 0395 - XX 1 CLIP,CABLE:NYLON 80009 3440395XX
- 65 344 - 0396 - XX 2 CLIP,CABLE:PVC 80009 3440396XX
- 66 333 - A440- 00 1 PANEL,FRONT: 80009 333A44000
(The panelwhicha characterisn’tbeingprintedon.)

- 67 407 - 3472- XX 1 BRACKET,ANGLE:LOWER,PANEL 80009 4073472XX

(ATTACHING PARTS)
- 68 210 - 0586 - XX 2 NUT,PL,ASSEM WA:4- 40 X 0.25,STL TK0435 ORDER BY DESC
- 69 211 - 0038 - XX 2 SCREW,MACHINE:4- 40 X 0.312,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 70 122 - 0184 - XX 1 ANGLE,RAIL:SUBPANEL MTG,RIGHT 80009 1220184XX
(ATTACHING PARTS)
- 71 210 - 0586 - XX 1 NUT,PL,ASSEM WA:4- 40 X 0.25,STL TK0435 ORDER BY DESC
- 72 211 - 0038 - XX 5 SCREW,MACHINE:4- 40 X 0.312,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 73 351 - 0855 - XX 1 GUIDE,PB:370BLEFT- STANDBY- RIGHT SWBD 80009 3510855XX
- 74 671 - B244- 00 1 CKT BOARD ASSY:LOR KEY( A14 ) 80009 671B24400
(ATTACHING PARTS)
- 75 210 - 0586 - XX 3 NUT,PL,ASSEM WA:4- 40 X 0.25,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 76 129 - 1128 - XX 3 .SPACER,POST:5.1MM,L,POLYCARBONATE 80009 1291128XX
- 77 150 - 1176 - 00 2 LT EMITTING DIO:RED( A14DS100,DS400 ) 80009 150117600
- 78 174 - 1832 - 00 1 CA ASSY,SP,ELEC:14,28 AWG,23.0 L,RIBBON(A14W140 ) 80009 174183200
- 79 366 - 0617 - XX 3 PUSH BUTTON:SILVER GRAY,9.6 X 4.2 X 8.5MM 80009 3660617XX
- 80 426 - 2336 - XX 1 SUBPANEL,TEST F:ALUMINUM 80009 4262336XX
- 81 333 - 3716 - XX 1 PANEL,FRONT: 80009 3333716XX
- 82 426 - 2331 - XX 1 FRAME:POLYCARBONATE 80009 4262331XX
- 83 343 - 1084 - XX 2 CLAMP,CABLE:NYLON 80009 3431084XX
- 84 407 - 3857 - XX 1 BRACKET,CMPNT:CKT BREAKER,ALUMINUM 80009 4073857XX
(ATTACHING PARTS)

9-24 370B Service Manual

 Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
- 85 210 - 0586 - XX 2 NUT,PL,ASSEM WA:4- 40 X 0.25,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 86 260 - 2499 - 00 1 CIRCUIT BREAKER:SPST,1.5A,250 VAC( S800 ) 80009 260249900
- 87 198 - 5468 - 00 1 WIRE SET,ELEC:( W410 ) 80009 198546800
- 88 337 - 3344 - XX 1 SHIELD,ELEC:PROTECTIVEBOX,PC 80009 3373344XX
- 89 337 - A851- 00 1 SUB PANEL(Printedmatter) 80009 337A85100

370B Service Manual 9-25

Mechanical Parts List

9-26 370B Service Manual

 66

89

Figure 9- 5: Front Panel: L-O-R

370B Service Manual 9- 27

Figure 9- 6: LV, L-O-R, Looping Circuit Boards

9- 28 370B Service Manual

 Mechanical Parts List

Replaceable mechanical parts list

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
6-1 441 - 1923 - XX 1 CHAS,TEST FXTR:GUARD BOX COVER,AL 80009 4411923XX
(ATTACHING PARTS)
-2 211 - 0661 - XX 4 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
-3 334 - 7730 - XX 1 MARKER,IDENT:MKD LOOPING INFO 80009 3347730XX
-4 334 - 6690 - XX 1 MARKER,IDENT:MKD CAUTION & DANGER 80009 3346690XX
-5 252 - 0719 - XX 1 PLASTIC SH,CHAN:0.047 X 0.063 THK,39.37 L 80009 2520719XX
-6 671 - 1183 - 04 1 CKT BOARD ASSY:LV RELAY( A9 ) 80009 671118304
(ATTACHING PARTS)
-7 211 - 0729 - XX 8 SCR,ASSEM WSHR:6- 32 X 0.437,PH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 23 196 - 3301 - 00 1 LEAD,ELECTRICAL:18AWG,6.0 L,W/LUG:(A9W10 ) 80009 196330100
- 25 671 - 1147 - 03 1 CKT BOARD ASSY:LOOPING( A35 ) 80009 671114703
- 26 211 - 0751 - XX 1 .SCR,ASSEM WSHR:M3 X 8 80009 2110751XX
- 27 342 - 0895 - XX 1 INSULATOR:POLYCARBONATE,LV CKT BD 80009 3420895XX
(ATTACHING PARTS)
- 28 210 - 3110 - XX 4 RIVET,SOLID:5.5MM L X 3.4MM OD,TRUSS,NYLON TK0BK 27 - 0601
- 29 210 - 1475 - XX .301393 .301917 4 WASHER,PLAIN:3.56ID X 7.94 OD X 0.8 THK 80009 2101475XX
(END ATTACHING PARTS)
- 30 671 - 1140 - 01 1 CKT BOARD ASSY:LOR RELAY( A34 ) 80009 671114001
(ATTACHING PARTS)
- 31 211 - 0504 - XX 6 SCREW,MACHINE:6- 32 X 0.250,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 32 198 - 5688 - 00 1 WIRE SET,ELEC:( A34W89 ) 80009 198568800
- 33 196 - 3276 - 00 1 LEAD,ELECTRICAL:18AWG,37.0 L,9- N( A34W94 ) 80009 196327600
- 34 198 - 5687 - 00 1 LEAD,ELECTRICAL:(A34W97 ) 80009 198568700
- 35 211 - 0751 - XX 2 .SCR,ASSEM WSHR:M3 X 8 80009 2110751XX
- 36 119 - 3414 - 02 1 HIGH V MODULE:W/18 RELAYS:( U800 ) 80009 119341402
(ATTACHING PARTS)
- 37 211 - 0504 - XX 4 SCREW,MACHINE:6- 32 X 0.250,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 38 210 - 0457 - XX 1 NUT,PL,ASSEM WA:6- 32 X 0.312,STL TK0435 ORDER BY DESC
- 39 307 - 1541 - 01 1 RES,FXD,FILM:1.1 OHM TO 25K OHM,2%,W/CONN:( R400 ) 80009 307154101
(ATTACHING PARTS)
- 40 211 - 0504 - XX 4 SCREW,MACHINE:6- 32 X 0.250,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 41 260 - 2328 - 01 1 SWITCH,THRMSTC:NC,OPEN,70.0,3.0 A,250V:( S90 ) S3385 5003F70B1- GUL
(ATTACHING PARTS)
- 42 211 - 0008 - XX 2 SCREW,MACHINE:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 43 198 - 5696 - 00 1 WIRE SET,ELEC:( W93 ) 80009 198569600
- 44 441 - 1922 - XX 1 CHAS,TEST FXTR:GUARD BOX,ALUMINUM 80009 4411922XX
(ATTACHING PARTS)

370B Service Manual 9-29

Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
- 45 211 - 0511 - XX 8 SCREW,MACHINE:6- 32 X 0.5,PNH,STL TK0435 ORDER BY DESC
- 46 210 - 0803 - XX 8 WASHER,FLAT:0.15 ID X 0.375 OD X 0.032,STL 12327 ORDER BY DESC
(END ATTACHING PARTS)
- 47 342 - 0774 - XX 8 INSULATOR,BSHG:4MM ID X 6MM THK,16MM OD 80009 3420774XX
- 48 361 - 1380 - XX 8 SPACER,RING:3MM L X 8.1MM ID 80009 3611380XX
- 49 220 - 0105 - XX 2 NUT BLOCK:4- 40 X 5.5MM,BRS TK019 2200105XX
(ATTACHING PARTS) 1
- 50 211 - 0661 - XX 2 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 51 344 - 0395 - XX 1 CLIP,CABLE:NYLON 80009 3440395XX
- 52 344 - 0396 - XX 2 CLIP,CABLE:PVC 80009 3440396XX
- 53 348 - 0949 - XX 1 GROMMET,PLASTIC:BLACK,RING,15MMID 80009 3480949XX
- 54 255 - 1108 - XX 1 PLASTIC CHANNEL:1000 X 4.4 X 5.0MM,NYLON 80009 2551108XX
- 55 255 - 0334 - XX 1 PLASTIC CHANNEL:12.75X 0.175 X 0.155,NYLON 11897 122 - NN - 2500 - 060
- 56 343 - 1288 - XX 1 CLAMP,CABLE:PLASTIC 80009 3431288XX
- 57 211 - 0504 - XX 1 SCREW,MACHINE:6-32 X 0.250,PNH,STL TK0435 ORDER BY DESC

9-30 370B Service Manual

 Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
7-1 441 - 1919 - XX 1 CHAS,TEST FXTR:MAIN,AL 80009 4411919XX
-2 342 - 0776 - XX 1 INSULATOR,FILM:370B 80009 3420776XX
-3 344 - 0396 - XX 1 CLIP,CABLE:PVC 80009 3440396XX
-4 343 - 0549 - XX 1 STRAP,TIEDOWN,E:0.098 W X 4.0 L,ZYTEL TK1499 HW - 047
-5 351 - 0774 - XX 3 GUIDE,SLIDE:PWR SW,POLYCARBONATE 80009 3510774XX
(ATTACHING PARTS)
-6 211 - 0038 - XX 3 SCREW,MACHINE:4- 40 X 0.312,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
-7 384 - 1703 - XX 1 EXTENSION SHAFT:PWR SW 80009 3841703XX
-8 214 - 3420 - XX 1 SPRING,HLCPS:10.0MM OD X 9.5MM L,CLE,SST 80009 2143420XX
-9 366 - 1767 - XX 1 PUSH BUTTON:BLACK,GREENINDICATOR 80009 3661767XX
- 10 122 - 0181 - XX 1 ANGLE,RAIL:LEFT 80009 1220181XX
(ATTACHING PARTS)
- 11 211 - 0502 - XX 4 SCREW,MACHINE:6- 32 X 0.188,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 12 122 - 0182 - XX 1 ANGLE,RAIL:RIGHT 80009 1220182XX
(ATTACHING PARTS)
- 13 211 - 0502 - XX 4 SCREW,MACHINE:6- 32 X 0.188,FLH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 14 441 - 1920- XX 1 CHAS,TEST FXTR:ALUMINUM,MID 80009 4411920XX
(ATTACHING PARTS)
- 15 211 - 0538 - XX 7 SCREW,MACHINE:6-32 X 0.312,FLH,STL TK0435 ORDER BY DESC
- 16 210 - 0457 - XX 1 NUT,PL,ASSEM WA:6- 32 X 0.312,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 17 344 - 0395 - XX 1 CLIP,CABLE:NYLON 80009 3440395XX
- 18 348 - 0949 - XX 1 GROMMET,PLASTIC:BLACK,RING,15MMID 80009 3480949XX
- 19 255 - 0334 - XX 1 PLASTIC CHANNEL:12.75X 0.175 X 0.155,NYLON 11897 122 - NN - 2500 - 060
- 20 407 - 3486- XX 2 BRACKET,XFMR:ALUMINUM 80009 4073486XX
(ATTACHING PARTS)
- 21 220 - 0410 - XX 6 NUT,PL,ASSEM WA:10- 32 X 0.375 HEX,STL 0KB01 511 - 101200 - 50 - 0
(END ATTACHING PARTS)
- 22 120 - 1677 - 01 1 XFMR,PWR,STU:CLCT SUPPLY,70V IN,40- 66HZ( T200 ) 80009 120167701
(ATTACHING PARTS)
- 23 212 - 0507 - XX 4 SCREW,MACHINE:10- 32 X 0.375,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 24 407 - 3854 - XX 1 BRACKET,ANGLE:ALUMINUM,SUPPORT 80009 4073854XX
(ATTACHING PARTS)
- 25 211 - 0538 - XX 4 SCREW,MACHINE:6- 32 X 0.312,FLH,100 DEG,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 26 198 - 5713 - 00 1 WIRE SET,ELEC:370B,W/D-SUB CONN( W491 ) 80009 198571300
(ATTACHING PARTS)
- 27 211 - 0661 - XX 2 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 28 386 - 5917 - XX 1 PLATE,CONN MTG:STEEL 80009 3865917XX
(ATTACHING PARTS)

370B Service Manual 9-31

Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
- 29 211 - 0510 - XX 2 SCREW,MACHINE:6- 32 X 0.375,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 30 174 - 1693 - 00 1 CA ASSY,SP,ELEC:34,28 AWG,130.0 L,RIBBON(W142 ) 80009 174169300
(ATTACHING PARTS)
- 31 211 - 0661 - XX 2 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 32 386 - 5484 - XX 1 PLATE,CONN MTG:MALE,STEEL 80009 3865484XX
(ATTACHING PARTS)
- 33 211 - 0510 - XX 2 SCREW,MACHINE:6- 32 X 0.375,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 34 119 - B105- 00 1 FLOPPY DISK DRIVE:( A24 )STAND.ACC 80009 119B10500
(ATTACHING PARTS)
- 35 211 - 0751 - XX 4 SCR,ASSEM WSHR:M3 X 8 80009 2110751XX
(END ATTACHING PARTS)
- 36 337 - 3588 - XX 1 SHIELD,ELEC:ALUMINUM 80009 3373588XX
(ATTACHING PARTS)
- 37 211 - 0658 - XX 4 SCR,ASSEM WSHR:6- 32 X 0.312,PNH,STL,POZ TK0435 17691 - 300
(END ATTACHING PARTS)
- 38 407 - 3855 - XX 1 BRKT,TEST FXTR:ALUMINUM,FDDMTG 80009 4073855XX
(ATTACHING PARTS)
- 39 211 - 0538 - XX 3 SCREW,MACHINE:6-32 X 0.312,FLH,STL TK0435 ORDER BY DESC
- 40 211 - 0507 - XX 3 SCREW,MACHINE:6- 32 X 0.312,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 41 334 - 6696 - XX 1 MARKER,IDENT:MKD DANGER 80009 3346696XX
- 42 671 - B128- 01 1 CKT BOARD ASSY:FDD INTERFACE ( A23 ) 80009 671B12801
(ATTACHING PARTS)
- 43 211 - 0661 - XX 4 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 45 174 - 1611 - 00 1 CA ASSY,SP,ELEC:34,28 AWG,9.0 L,RIBBON(A23W200 ) 80009 174161100
- 46 174 - B903- 00 1 CA ASSY,SP,ELEC:( A23W100 )
- 47 119 - 3477 - 02 1 RELAY MODULE:W/8 RELAYS (U300 SHOULD BE CHANGED 80009 119347702
WITH A10C322 20 PF.)( U300 )
(ATTACHING PARTS)
- 48 211 - 0244 - XX 4 SCR,ASSEM WSHR:4- 40 X 0.312,PNH,STL TK0435 7772 - 312
(END ATTACHING PARTS)
- 49 337 - 3629 - XX 1 SHIELD,ELEC:INPUTRELAY MODULE,AL 80009 3373629XX
- 50 671 - 1238 - 02 1 CKT BD ASSY:KEY INTERFACE( A13 ) 80009 671123802
(ATTACHING PARTS)
- 51 211 - 0661 - XX SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 54 671 - B212- 00 1 CKT BOARD ASSY:SENSE( A10 ) 80009 671B21200
(ATTACHING PARTS)
- 55 211 - 0661 - XX 6 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
- 56 129 - 0713 - XX 6 SPACER,POST:19.05MM L,W/4- 40 THD EA END 80009 1290713XX

9-32 370B Service Manual

 Mechanical Parts List

Replaceable mechanical parts list (Cont.)

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
- 57 211 - 0538 - XX 2 SCREW,MACHINE:6- 32 X 0.312,FLH,STL TK0435 ORDER BY DESC
- 58 129 - 1328 - XX 4 SPACER,POST:15MM L,4- 40 THD,BRASS 80009 1291328XX
- 59 343 - 1446 - XX 2 RETAINER,CKT BD:12.7MM L,NYLON 80009 3431446XX
- 60 213 - 0146 - XX 2 SCREW,TPG,TF:6- 20 X 0.312,TYPE B,PNH,STL TK0435 ORDER BY DESC
- 61 129 - 1131 - XX 2 SPACER,POST:12.7MM L,4- 40 THD,BRASS 80009 1291131XX
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 62 214 - 3877 - XX 1 .HT SK,CKT BD:AL 80009 2143877XX
(ATTACHING PARTS)
- 63 211 - 0661 - XX 3 .SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
(END ATTACHING PARTS)
- 77 671 - 1096 - 03 1 CKT BD ASSY:CONFIG.RELAY( A33 ) 80009 671109603
(ATTACHING PARTS)
- 78 211 - 0661 - XX 4 SCR,ASSEM WSHR:4- 40 X 0.25,PNH,STL TK0435 ORDER BY DESC
- 79 129 - 1328 - XX 4 SPACER,POST:15MM L,4- 40 THD,BRASS 80009 1291328XX
(END ATTACHING PARTS)
CKT BOARD ASSY INCLUDES:
- 86 174 - B904- 00 1 CA ASSY,SP,ELEC: 80009 174B90400

370B Service Manual 9-33

Mechanical Parts List

9-34 370B Service Manual

 86

Figure 9- 7: FDD, Config. Relay, Sense Circuit Boards

370B Service Manual 9- 35

 6
5

Figure 9- 8: Accessories

9- 36 370B Service Manual

 Mechanical Parts List

Replaceable mechanical parts list

Fig. &
index Tektronix part Serial no. Serial no. Mfr.
number number effective discont’d Qty Name & description code Mfr. part number
STANDARD ACCESSORIES

070 - A838- 50 1 USER MANUAL,370B TK2548 PER TEK P/N

159 - 0260 - XX 1 FUSE,CARTRIDGE:2A,250V,MEDIUM- BLOW 80009 1590260XX
159 - 0259 - XX 1 FUSE,CARTRIDGE:4A,125V,MEDIUM- BLOW 80009 1590259XX
337 - 3344 - 02 1 SHIELD,ELEC:PROTECTIVECOVER 80009 3373344XX
063 - 3341 - XX 1 UTILITY SOFTWARE(FD) 80009 0633341XX
-------- 1 A1001,TEST ADAPTER:BLANKADAPTER
-------- 1 A1002,ADAPTER,TEST:IN- LINE ADAPTER
-------- 1 A1005,ADAPTER,TEST:AXIALLEAD ADAPTER

8-1 161 - 0066 - 00 1 CA ASSY,PWR:3,18 AWG,250V/10A,98 INCH,STR S3109 161006600

(STANDARD ONLY)
-2 161 - 0066 - 09 1 CA ASSY,PWR:3,0.75MM SQ,250V/10A,99 INCH S3109 86511000
(OPTION A1 ONLY)
-3 161 - 0066 - 10 1 CA ASSY,PWR:3,0.1MM SQ,250V/10A,2.5 METER S3109 BS/13- H05VVF3G0
(OPTION A2 ONLY)
-4 161 - 0066 - 11 1 CA ASSY,PWR:3,1.0MM SQ,250V/10A,2.5 METER S3109 198 - 000
(OPTION A3 ONLY)
-5 161 - 0157 - 00 CABLEASSY,PWR,:3 X 0.75MM SQ,250V,7.0 L TK1267 ORDER BY DESC
(OPTION A5 ONLY)
-6 161 - 0304 - 00 1 CABLEASSY,PWR,:3 X 1.0MM SQ,250V/10A, 2.5 METER
(OPTION AC ONLY)

OPTIONAL ACCESSORIES

070 - A838- XX SERVICE MANUAL,370B

-------- A1003,TEST ADAPTER:TO - 3/TO - 66 80009 070A83800
-------- A1007,TEST ADAPTER:4& 6 LEAD TRANSISTOR 80009 0707780XX
-------- 1 A1009,TEST ADAPTER:4& 6 LEAD FET
-------- 1 A1010,TEST ADAPTER:IC
-------- 1 A1023,TEST ADAPTER:SOT23,SMDADAPTER
012 - 0991 - 00 1 GPIB CABLE :2m
016 - 0930 - 00 1 RACK MOUNT KIT
K475 1 CART
1
1
1

370B Service Manual 9-37

Mechanical Parts List

9-38 370B Service Manual