USEFUL INFO.

Collection By Pravin Mevada

Error reader.
The BE-3D chassis supports the use of the Error Reader. This jig, is available under part number S-188-900-10
(price code S).

The displayed code shows the actual error of the TV set. Refer to the service manual or the table below for an
explanation of those codes.

ERROR CODES
02 - Protection circuit trip <ANY TIME>
03 - IIC SCL LOW <POWER UP ONLY>
04 - IIC SDA LOW <POWER UP ONLY>
05 - IIC SDA and SCL LOW <POWER UP ONLY>
06 - Jungle/chroma controller no acknowledge <POWER UP ONLY>
07 - Video switch no acknowledge <POWER UP ONLY>
08 - Tuner no acknowledge
09 - MSP no acknowledge
10 - NVM no acknowledge
11 - M3L TXD LOW <POWER UP ONLY>
12 - M3L RXD LOW <POWER UP ONLY>
13 - M3L ENABLE LOW <POWER UP ONLY>
14 - M3L TXD AND RXD LOW <POWER UP ONLY>
15 - Compact Text test fail <POWER UP ONLY>
16 - AV switch cannot power on reset
17 - Cannot initialise jungle
18 - NVM acknowledge fail after initialisation
19 - Multiple devices with no acknowledge <POWER UP ONLY>
20 - Compact Text run-time failure
21 - AVSWITCH response failure after power up
22 - JUNGLE/CHROMA controller response failure after power up
23 - Compact Text does not respond
24 - Sound processor run time failure
25 - M3L bus clock low time-out after data sent (run time failure)
26 - M3L bus clock low time-out afetr data sent (power up)
27 - M3L bus clock low time-out afetr data sent (initialization)
28 - DSP run-time failure.

Replacement of HV transformer.
Two types of high voltage transformer are used (removable or fixed focus cable). When replacing a line
transformer, replace using the original type.
Type Focus cable Part no.
A Removable 1-453-169-12
B Fixed 1-453-220-11

DEFLECT
Lines tearing when hot.
[32in models only]. Replace line driver transformer T804.

No sync in TXT mode.

Replace IC1001.

PICTURE

 

Horizontal interference in picture during first half hour.
IC606 is defective. Therefor unstable +9V (pin 3 of IC606). Replace 9V regulator IC606.
Ref. Description Location Part no.
IC606 LM2940T-90 D-board PSU 8-759-267-25

Visible arcing interference on screen when appliance does function. Intermittently switches off when switched
on.
Replace line output transformer T803.

Partially blanked horizontally.

Check zener diode D817 (RD5.6ESB2) in blanking circuit, for leaks.

Overbright, nearly negative picture.

Access service mode and enter TT07 to clear.

AUDIO
Hum and/or buzz of the headphones and/or speaker when vol. is low.
Deflection unit generates interference. On board A, solder side, add a thick wire AWG18 200mm long between
pins 6,7 and 8 of IC203 and pins 29 and 30 of CN1. Given its critical position, the wire must be kept away from
board A.
Part no. Ref.
190090227 Wire AWG18

No sound. Headphones OK.

Fau;t 1: [PS6001 O/C]. Replace audio output chip IC1200 (TDA7264).

Distorted or loud crackling from audio.

Check audio demodulator/processor chip IC202 (MSP3410).

POWER
POWER
EHT comes up briefly then nothing. No error code.
[Excess current protection system operating]. Check line output transformer T803.

Intermittently switches off when switched on. Visible arcing interference on screen when appliance does
function.
Replace line output transformer T803.

Locks when hot.

Replace IC202 (MSP3410).

Shuts down when hot.

Replace IC202 (MSP3410).

FUNCTION
No TXT. No OSD.
Check zener diode D817 (5.1V) on main PCB.

Comes on then switches to standby. Standby LED flashes twice.

(1) Check field output chip IC500 (STV9379).
(2) [OK if D505 disconnected]. Check zener diode D505 (MTZJT7736A) for leaks.
(3) [No change if D505 disconnected]. Replace memory chip NVM IC2.

 

 Does not got into standby mode completely; picture disappears but line continues to run.
(1) Check Q602, Q603 and Q604 in standby switching circuit. Check reservoir capacitor C615.
(2) [Above components replaced; HT not at 135V]. Replace error detector chip IC602 (SE135N).

Pulses in and out of standby. RY600 clicks each time.

Check Q601 (2SC3852A), D603 (6.8V) zener and R634 (22R) on primary side of PSU.

Degaussing incomplete.
Replace relay RY600 with part number 1-755-018-11.

TUNING/MEMORY
Intermittently channels change.
Replace tactile switches S9001 and S9002 on D board.

GEOMETRY
E-W bowing. Excessive width.
Check R870 (1R/1W).

OTHER
No OSD. No TXT.
Check zener diode D817 (5.1V) on main PCB.

Intermittently volume bar appears.

Replace tactile switches S9001 and S9002 on D board.

Incomplete or messy OSD and menus. TXT OK.

Replace IC1001.

 

 Sony IK Circuit……. Explained by Dan Mundy, CET/CSM
scan line. The IK circuit then matrixes back to the jungle IC or the IC itself is
them together, amplifies the 3 pulses and bad Some times the jungle IC has small
send it back to the jungle IC. Mylar caps off of it and if there they
have been known to short. Sometimes
Using a scope with delayed sweep or set the caps are built into the jungle IC and
at the vertical rate and expended 10X you can still short.
should be able to see the 3 pulses at the
IK output from the CRT board and Many times the IK circuit just goes out
note that the amplitude will grow or of tolerance meaning the current drawn
shrink depending on the screen setting. by one crt is no longer within acceptable
I have posted this before as a trouble- range and the picture is blanked.
shooting aid. It should explain what is If one color is missing then you have If this is the case then increasing the
happening. an amp circuit problem for that color. screen voltage will solve, for a while,
the complaint.
I don't have the manual in front of me If none of the pulses are there and
so this may be a little generic. The IK they go in from the jungle IC then Daniel Mundy, CET®/CSM
circuit sends out a 100% white pulse look for a bad IK amp transistor. HiFi Buys a Tweeters Etc. Company
during the vertical blanking interval. Atlanta, GA 30331
There is a pulse for red then green and If the pulses are there but do not vary
lastly blue. Each pulse is on a different with changing screen voltage the feed-

See The Next Three Pages

To Bypass This Circuit
For Test Purposes

Use at your own Risk. The Speaker, its

DISCLAIMER Writers and Staff, and Nesda of Ohio
assume NO responsibility for damage to
Information presented here is derived from persons or property as a result of any
many sources and is believed to be correct information printed herein.
at time of printing. We make no guarantee,
express or implied of the accuracy, efficacy, Opinions stated are those of the author and
or safety of any of the techniques not the Nesda of Ohio Newsletter. Opinions
published. It is not intended to replace stated are believed to be true, and are
Manufacturer's Recommendations or offered in the spirit of helping other
good Safety and Troubleshooting servicers but may have no basis in fact.
practices.
 Sony IK Circuit Bypass By Joe Sopko, CET
Contributed By Jorge Miret And Luis Alberto Tamiet

overscanned part of the screen if the drive amplifiers, in the CRT, or in the IK
Sony television sets of recent years vertical height (VSIZ) in the Menu is circuit.
(1994-95 & more) contain circuits which reduced slightly. This circuit, besides to
monitor the current of the CRT cathodes. verify the correct operation of the CRT, The next step, is to verify the state of the
The microprocessor in combination allows to make automatic adjustments CRT. If it has low emission in some of
with the "jungle" chip and a series of within the IC jungle, to compensate the the cathodes, or if it has some internal
transistors and other components in the small differences of emission between the short it can cause that IK circuit to stay in
circuits corresponding to the three cath- cathodes and to maintain the correct color "cut". For this it is advisable to use a Kine
odes, then automatically adjust the bias of of the image. The current of the cathodes Checker. If it is not had one, the follow-
each individual gun to compensate for is detected by 3 Detector circuits put in ing verification can be made: With the
Kinescope aging. between the exciting amplifiers and TV operating, momentarily place a 15 or
each one of the cathodes. These circuits, 20K 2W resistor, between ground and
Unfortunately for the owner, they also send a signal, proportional to the current each one of the cathodes (KR, KG and
will blank the picture when the Kine of each one of the cathodes, to a IK KB), one at a time. This will result in
slumps too low. Some tech's have been Buffer circuit, from where they are sent to the corresponding color illuminating
able to "Rejuvinate" the Kine & restore the jungle chip. In many equipment these brightly. The intensity must be similar
performance, while others have wondered circuits are formed by discrete compo- when doing the test in the three cathodes.
if there was a way to bypass that IK nents (transistors, diodes, resistance, etc.) If some of the colors does not appear or it
circuit. That answer has been always but in more recent models, all the exciting does in tenuous form, it indicated an ex-
been "NO" --- Until now. stage of the CRT and the components of hausted or defective CRT. (This is not a
IK circuit are included in a single very precise test. It is better to use a Kine
Jorge Miret, of J.C.Electronic Repairs in integrated circuit like the TDA6108. Checker, but nevertheless, this test could
Puerto Rico has discovered a circuit Almost from the moment at which the aid to determine if some of the guns, is
modification which will allow a bypass of equipment is ignited, the "jungle" chip defective or with very low emission).
that circuit. It is found on a Spanish- sends the respective pulses to each one of
Language website the output pins, while it maintains a "cut" To deactivate or "to deceive" the IK cir-
www.comunidadelectronicos.com/ or "muting" of video (black screen). As cuit sometimes can be useful. The
articulos/IK.htm the cathodes reach the temperature neces- circuit modification below will "deceive"
which makes it a bit tough on us Gringo's, sary to emit electrons, the current of such, the IK circuit into deactivating the video
but "not to worry". Google, the ever help- generates in the respective detector cir- blockade that it causes. This can be done
ful search engine is capable of translating, cuits, a pulse similar to the applied one by disconnecting the line of the IK buffer
as you've learned in another article and whose amplitude is proportional to and placing three diodes of the type
published within the pages of "The the current of the cathode. To see the 1N4148 between the pins of the inte-
Speaker". image on the screen, When the pulses in grated jungle, as it is shown in the figure.
the IK circuit reach certain amplitude, the With this modification, the pulses from
Following is a machine-translation of that "cut" of video is deactivated and the im- the output of the jungle chip are
webpage, aided by your reporter where age appears. The lack of video (black re-introduced into the IK line of the chip
necessary. screen), in these TV Sony, sometimes which then deactivates the video
causes confusion between the technicians, blockade, allowing the image to appear
A diagram of the circuit modification is because when not having an output of on the screen. If the image does NOT
provided. It involves cutting a trace and signal from the jungle chip, tend to appear, and having made the verifications
the addition of 3 diodes. suppose that the problem is in the Jungle given earlier, is possible that the inte-
Chip. grated jungle (or some component
Translation for Gringo's: associate) is defective.
When faced the repair of a recent TV that
Following is a brief description of the presents absence of Video (black screen), Granted, The translation leaves a bit to be
Operation of the IK circuit. From each we must make the following steps: To desired (you should have tried reading it
output of the Jungle Chip (R, G, B) exits increase G2 screen voltage. If the screen before I "Helped" it along). I make no
a pulse, three pulses in all, one to cathode is illuminated with "raster" (swept) nor- claim to be a linguist— My parents never
of the Kine. These pulses are at the hori- mal, we can discard the possible prob- even spoke Hungarian around me, but I
zontal sweep rate, so that it activates lems in the circuits of sweeping. (a defect believe that this is more information than
during the exploration of a line. These in the Vertical circuit, can cause the same we've ever seen about this IK circuit
lines are not visible in the screen, since symptom) This also allows us to quickly before.
they are sent during the beginning of the verify the necessary voltages for the
"vertical sweeping", in the area of operation of the CRT (filament, anode, ( Cont. Next Page )
"blanking", but they can be seen in the G2). If these voltages are correct, is very
possible that the problem is in the Kine
The article that you've just read was con-
tributed By Jorge Miret and appears to be
written by Luis Alberto Tamiet on the
website listed in the first paragraph. As
the entire site is in Spanish, I am not sure
of the actual author.

The Speaker would like to thank Both of

these Techs for adding to our store of
knowledge. Take the information for
what it's worth, I've not tried it, and
neither has the contributor so we can't
speak of it's efficacy from personal
experience. It is presented as another di-
agnostic tool to determine whether the
blanking is caused by the jungle chip or
the kine.

Of course, no tech would ever leave

the bypass circuit in as a permanent
measure, nor would "The Speaker"
ever recommend a modification not
authorized by the manufacturer. If
you try this, we'd like to hear of your
experience and opinion as to it's
value.

Hey,
It Works !!
See follow-up article
next page.

Author Joe Sopko

Tried This Procedure
 Sony IK bypass, IT WORKS !! By: Joe Sopko CET

Recently, The Speaker printed an Jungle Chip (CXA1870). Those 3 diodes I'm glad to report that the modification
article describing a procedure to bypass and a cut of a foil trace on the PCB are all performs as promised. BEFORE the
the Sony IK circuit. The procedure came that the mod involves. Real Easy, Takes Mod, the picture would blank at the low
from a Latin American site, and at the only a couple of minutes. Figure 2 shows end of the screen control, would
time of printing we didn't know of anyone how the diodes are connected schemati- reappear at mid to high range, and then
who had actually tried it or if it was cally. blank again at very high position of
actually effective...Heck, it took us long the control. AFTER the Mod, The pic-
enough just to translate the thing! Be aware that there are different jungle ture was present throughout the entire
chips involved in different sony chassis. rotation of the screen control. I assume
Subsequent to that time, a Sony Some use the CXA1465, and some use that Sony's intent was to prevent a
KV20S20 came into Consumer Service in the CXA1870 (and I have no doubt poor picture from being seen as the kine
South Euclid Ohio with a Black Screen that there are others, too). I have put the aged beyond limits. With this
(has sound). Turning up the Screen affected pin numbers for these 2 chips in modification, you can watch a crappy
Grid restored the picture, so it looked as figure 2 for your information. Also be picture throughout the entire range of
though this was a candidate to determine aware that a particular chassis may use the control if you so desire.
the efficacy of that Bypass Mod. Seized "either" of 2 chips. The chassis that I was
by the curiosity that marks all working with had Naturally, this procedure is
technicians, I installed the components the PCB roadmapped for a 48 pin chip, presented only as a Test procedure to
mentioned in that article from The but actually had a 42 pin chip determine if the IK Blanking Circuit
Speaker. installed. Needless to say, the pin mark- is indeed keeping the picture from
ings on the PCB's surface were
appearing. No technician would
As you can see in Figure 1, there are 3 incorrect. (Tech's are nothing if not
diodes riding like an outrigger on the adaptable) ever leave the mod in as a permanent
fix and The Speaker would never
recommend any procedure contrary
to the manufacturer's approved
practices.

FIGURE 1

Photo by Flash Sopko with the new

NesdaOhio Digital Camera
S ® Training Manual

WEGATM Direct View

Television
AA-2W Chassis
Models: KV27FV15 KV32FV15
KV36FV15 KV32FS10
KV36FS10 KV32XBR250
KV36XBR250

Circuit Description and Troubleshooting

Course: CTV-26
 Sony Service Company
A Division of Sony Electronics Inc ©1999
All Rights Reserved
Printed in U.S.A.

S is a trademark of Sony Electronics

Circuit Description
and Troubleshooting:
Model: KV27FV15 KV32FV15
KV32FV15 KV36FV15
KV32FS10 KV36FS10
KV32XBR250
KV36XBR250
Prepared by: National Training Department
Sony Service Company
A Division of Sony Electronics Inc.

Course presented by _____________________________________

Date___________________________________________________
Pravin Mevada
Student Name ___________________________________________
 S
SEL Service Company
A Division of Sony Electronics Inc.
1 Sony Drive
Park Ridge, New Jersey 07656

CTV261299 Printed in U.S.A.

 Table of Contents
Features 1 Soft Start/Regulation/Foldback 19
Board Descriptions 2 Soft Start 19

Picture Tube Defect Symptoms 3 Regulation 19

Foldback 19
V Chip 5
Introduction 5 Secondary Voltages 21
What is V Chip Technology? 5 +135 Volts 21

Parental Guideline Rating System 5 +12 Volts 21

Parental Control Menu 6 +9 Volts 21

Decoding 6 +5 Volts 21
Audio B+ 21
Power Supply Block 7
Power Supply Protection 25
Standby Power Supply 9
+135 Over Current Protection 25
Converter Operation 9
Foldback 25
Regulation 9
Vertical Deflection 27
Power On/Degaussing 13
Power On 13 Horizontal Deflection Block 31
Degaussing 13 Horizontal Out 33
Converter 15 Pincushion 35
Initial Start Up 15 H Protect 37
Soft Start 15 Appendix - Service Bulletins i
Regulation 15
Troubleshooting 17
 1
The table below shows which features are different between models.
Features
KV27FV15 KV32/36F KV32/36FS KV32/36XB
V15 10 R250
Introduction
Audio 15Wx2 15Wx2 10Wx2 15Wx2
This course covers AA2W chassis Sony direct view televisions. These Power
sets are part of the WEGA line which contain the flat screen FD Trinitron
2 Tuner PIP Yes Yes No Yes
picture tubes. This course describes the Power Supply, Deflection and
Protection circuits with a twist of practical troubleshooting tips and known Component N/A* 1 1 1
solutions. In addition, this course reviews picture tube diagnostics and Video Input
solutions, plus the latest information on the V-Chip. Remote N/A N/A N/A Yes
The US models listed below use the AA2W chassis design. Infrared
Headphones
KV27FV15 KV36FS10
Comb Filter 3 line 3 line 3 line 3D
KV32FV15 KV32XBR250
S-Link Yes Yes No Yes
KV36FV15 KV36XBR250
KV32FS10 *One significant difference between the 27FV15 model and the rest of the
models is the lack of the component input. This model will have a much
The following is a list of features that all of these models have. simpler video path because of this.
3D Digital Comb Filter analyzes the picture along the three dimensions
FD Trinitronfi Picture Tube Trinitone Color Temperature
of height, width and time, to minimize even subtle picture artifacts.
Adjustment
3-Line Digital Comb Filter analyzes three TV scanning lines at a time for
Dynamic Picture Processor Velocity Modulation better color.
Dynamic Focus Circuitry MTS Stereo TV Decoder3 Vertical Aperture Compensation sharpens picture definition and edge
Customer Tilt Correction dbxfi Noise Reduction detail on the vertical plane producing sharp horizontal edges.
Auto Pedestal Clamp DAC Speaker System Steady Sound™ Automatic Volume Control with BBE equalizes the
Magnetic Quadra Pole Focus SRS 3D Audio Effect volume levels so there is consistency between programs and commer-
cials.
V-Chip Parental Control 1Front/2Rear A/V Inputs
Auto SRS® Sound Enhancement creates a vivid stereo image using
Program Palette Presets CaptionVision (CC)/ XDS (Extended the principles of human hearing to make the sound appear to come from
Data Service) widely separated speakers.
Vertical Aperture Compensation Steady Sound With BBE Magnetic Quadra Pole reduces beam spot distortion and improves cor-
ner-to-corner focus, as well as picture sharpness.
 Board Descriptions

Name Description
A Micon, Y/C Jungle, Tuner, Pincushion, H Deflection, V Deflection, H Deflection, Syston
AK Audio Amp, Surround Sound, Sub tuner, S-Link
C RGB Drive
G Power Supply
HA Front A/V Inputs, Menu Buttons
HB IR Detector
HX Buttons
T (XBR Only) IR Headphones
UX (XBR Only) 3D Comb Filter, A/V Switch, Audio Control, SRS, Chroma Decode, PIP Encode
UY (All Except XBR) 3 Line Comb Filter, A/V Switch, Audio Control, SRS, Chroma Decode, PIP Encode (except FS10 model)
WA Velocity Modulation, Quadrapole

HX
C
T
(XBR only)
HB

WA
HA
G
A
AK
UX/UY
XBR/Non-XBR

CIRCUIT BOARDS LOCATION

2
 3

Picture Tube Defect Symptoms Bright picture

with retrace
Grid 2 to
high
Symptom is
that all three
Reduce G2 / screen voltage
to the lowest setting.
lines and/or voltage colors are Vary focus control to both
Overview poor focus. Grid 3 bright. limits several times.
leakage. Put on safety apparel.
Below is an excerpt from the CTV-25 course. It shows several picture
Place the tube face down
tube defect symptoms, some of which can be repaired without changing and lightly tap the neck to
the tube. dislodge the particle.
Defective Picture Tube Symptoms RGB Rainbow. Aperture Rainbow of A loose aperture grill is
(see rainbow grill was colors can dangerous and may cause
Symptom Suspect Check Procedure
picture) unseated in start at the top tube implosion. Use all
Dark picture or Heaters Apply 6Vdc to Clean the CRT pins and transit. or bottom safety precautions. Do not
one color Open the heater examine the socket for (bottom jar set. Transport TV face
missing. terminals. corrosion. rainbow down.
Some heaters Apply 6Vdc to the CRT shown).
are connected heater pins, looking for a
Purity / Beam The TV s Same color Do not manually Degauss
in parallel, glow in all three heaters.
landing is off. degaussing blotches the picture tube with a
others in Then if a heater(s) does not
circuit did remain at that strong degaussing coil **.
series but all glow, replace the picture
not area of the Repair the TV s degaussing
take 6Vdc. tube.
demagnetiz screen circuit. The thermistor or
Dark picture Grid 1 to There should 1. Unplug TV and remove e aperture regardless of cold solder is usually at
Grid 2 be infinite C board. grill metal picture screen fault.
short. resistance 2. Apply 15-20Vdc support. changes.
between the between the G1 and G2
* Only the heater pins should have resistance. All other pins have infinite (∞)
G1 and G2 pins to vaporize the
resistance to each other and to either heater pins.
pins. short. Current limit the
power supply to 1 Amp. Used picture tubes that have a heater-cathode leakage/short have a low
Bright red, Heater Remove the Replace tube. restoration success level.
green or blue Cathode R, G or B ** Do not manually Degauss. New 27 35 picture tubes are magnetically
picture. short. video input to conditioned for optimum beam landing. Strong manual degaussing will
One color the CRT for destroy this conditioning. Applying disc magnets (P/N = 1-452-094-00) to the
OR
retrace lines the bright bell of the picture tube is the only way to compensate for lost magnetic
Cathode to
may be color. If that conditioning. The Sony manual degaussing tool can be used to degauss
Grid 1
present. color is still these tubes because of its reduced field intensity (P/N = 7-700-781-01).
short.
Retrace lines bright, the
are diagonal tube is bad.
lines that run There should
from lower left be infinite
to the upper resistance
right corner. between any
CRT pin to
either Heater
pin. *
4
 5

V Chip Parental Guideline Rating System

The ratings can be separated into three categories. They are TV Ratings,
Movie Ratings and Unrated. The following table shows the ratings for the
Introduction
three categories.
“Pursuant to the Commission’s rules, half of all new television models 13
inches or larger manufactured after July 1, 1999, and all sets 13 inches or
larger manufactured after January 1, 2000 must have V-Chip technology.
Set top boxes that allow consumers to use V-Chip technology on their
existing sets are now available.” This quote from the FCC web page
defines the guidelines that manufacturers of television receivers must fol-
low. No matter what your personal feelings on the ratings issue, you will
be forced to deal with it as a technician. Here you will be given informa-
tion on what V chip technology is, how it is implemented in Sony televi-
sions and what to do if the customer forgets their password.
Broadcasters are not required at this time to transmit ratings for their pro-
gramming. At this time, however, the major networks are broadcasting
ratings but all of their affiliates are not. In addition, many of the popular
cable stations are broadcasting V Chip ratings.

What is V Chip Technology?

The V Chip system allows broadcasters to send data that contains rat-
ings. The television receiver processes this data and acts according to
the programming wishes of the user. The user’s television has menu The TV Ratings are both age and content based. The level of the content
options for determining which programs should be blocked. These op- rating is also based on age. For example, a program with a TV-PG V
tions are compared to the data received and programs are blocked ac- (Violence) rating may contain moderate violence, while a TV-14 V rating
cordingly. may contain more intense violence.
The consumer may choose to block Unrated programs. If they do this,
they need to be aware that emergency broadcasts, political programs,
sports, news, public service announcements, religious programs and
weather programs may be blocked.
Parental Control Menu Here the user can select ratings by age or content. If they do not want
violence of any kind to be seen but are not offended by strong language,
Sony V Chip equipped televisions contain the Parental Control Menu,
they can select the V for PG-14. This will block all V settings above PG-
which is located in the Setup section. When it is selected, the user will be
14.
asked for a 4-digit password. After this password is entered, the user will
be asked to confirm it. After confirmation, the password is set. Anytime Decoding
the user wants to modify the Parental Control Menu, the password must The Parental Guideline Rating that is broadcast by the programmer must
be entered. Note: If the customer forgets their password, the master be decoded at the receiver. This rating data is placed on Line 21 Field 2
Password 4357 can be entered. This allows the customer to reset or Line 284.
their password. No settings can be changed until a new password
is entered.
When you have entered the password, an options menu will be displayed.
The options are as follows.
Parental Lock: This is used to enable or disable the ratings system. This
is done by selecting On or Off.
Rating: There are four ratings that can be selected.
The preceding waveform shows the contents of Line 21 Field 2. We see
ƒ Child – The child selection is used to enable only TV-Y, TV-Y7, TV-G that right after the burst signal on the back porch of the horizontal sync is
and G ratings. a clock signal. This clock is used to inform the decoder that data is com-
ƒ Youth – The youth selection is used to enable TV-PG and PG ratings. ing and to synchronize the decoder and data. Since there is other XDS
Ratings considered lower than these will also be enabled. (Extended Data Services) data on this line, the first three data bits are
ƒ Youth Adult –Tthe youth adult selection enables TV-14 and PG-13 known as the identifier. Data 001 identifies the data as Parental Ratings
ratings in addition to lower ratings. data. Then two bytes of data are sent which contain the rating informa-
ƒ Custom – The custom selection allows you to tailor the age and con- tion. The first byte contains information about the age rating and the
tent ratings to your liking. The picture below shows the menu that will second contains information about the content rating.
be seen when custom is selected.
Ratings are decoded by the System Control IC in Sony televisions. These
ICs contain the programmed information and the decoder. When a pro-
gram is determined to have a rating that should be blocked, this is recog-
nized. The System Control IC also contains the OSD outputs. When the
program is to be blocked, the OSD section outputs a black screen along
with the blocked show’s rating. For example, if the Parental Controls are
set to Child and the received program is rated TV-14, the screen will be
black with TV Rating TV 14 in white letters.
There is also an additional V-Chip IC used on sub-tuner video. This pre-
vents blocked programs from being displayed in the PIP window.

6
 7
Shortly after the click of the power relay at turn ON, another click is heard.
Power Supply Block This click is RY601 Degauss Relay closing. This may be accompanied by
a hum sound that indicates the operation of the degaussing coils. After
Overview the AKB circuit operation is considered normal, the degaussing relay opens.
The power supply in the AA2W chassis is located on the G board. AC This is the third click that occurs about 8-10 seconds after the unit is
from the outlet is applied to a series of line filters and protection devices turned ON.
and eventually applied to the standby supply, AC rectifier and degauss During operation of the set, the +135 volt line is monitored for DC protec-
circuits. The Standby supply is a switching supply whose output is ap- tion. This protection circuit is used in conjunction with the latch to switch
plied to a 5-volt regulator. The output from the regulator exits the G board the Power ON line LOW if a failure should occur. This will turn RY600
at CN641/10. It is applied to various components in the set that need to Power Relay OFF and turn the power supply OFF. In addition to this
be powered when the set is OFF. These include the Micon and the re- protection circuit a foldback circuit can also shut down the power supply.
mote sensor. The foldback circuit compares the secondary’s +12 volt output to a volt-
When the set is turned ON by using either the power button or the remote age on the primary side. If there is a problem with either one of these
control, 5 volts is applied to CN641/11. This 5 volts is used to turn RY600 circuits, the set will shut down.
Power Relay ON. When the relay closes, a click is heard. Closing the
relay allows the rectified ac voltage to be applied to the converter circuit.
The converter begins operation when this voltage is applied. The power
ON line is also applied to the soft start circuit. The soft start circuit holds
the B+ voltage low while the power supply filters charge by controlling the
voltage present across the control winding. The control winding deter-
mines the switching frequency of the converter. After soft start operation
is complete, the regulation circuit takes over operation of the control wind-
ing. This allows the converter’s output to be coupled through T605 to the
secondary supplies. These supplies supply power to the rest of the set.
The regulation circuit monitors the +135 volt line.
 T605

CONVERTER
AC 12V
AC 8
RECT. + SECONDARY 9V
INPUT 6
RY600 SUPPLIES
7
B+ 135V 1
2

TO
CN1641
A BOARD
DEGAUSSING DGC 12
+
RY601 +135V
SOFT START
FOLDBACK POWER ON 11
DGC REGULATION
10 CN641
STANDBY 5V
DC
G BOARD PROTECTION
& LATCH CN642
5V
5
AUDIO B+ TO
1
2
CN1643
AUDIO GND AK
STANDBY 3
BOARD
POWER 5V 4
SUPPLY REG

POWER SUPPLY BLOCK 7CTV26 1/1/00

8
 9
The waveforms below show what will be seen at Q621.
Standby Power Supply
Overview
The standby power supply is a switching power supply used to create
Standby 5V. The Standby 5V line is used to power the Tuning Micon and
EEPROM and any other circuits which need power when the set is OFF.
Converter Operation
Operation of the Standby power supply begins when the set is plugged in. Q621/D - 50 mv, 10 us Q621/G - 1 V, 10 us

The AC line voltage is applied across the standby power supply. The AC
low side is ground for this circuit. The AC high side is applied to a half
wave rectifier consisting of D621 and D622. Two diodes are used so that
there will be protection should one of them fail. This voltage is then ap-
plied to T621/1 SRT Input through R639. R639 is a fusible resistor used
for current limiting and failure protection. It will open if the standby switch-
ing circuit draws excessive current. Please note that the board has T621
SBT silk-screened on it. This differs from the service manual, which calls Q621/S - 1 V, 10 us

T621 SRT. Regulation

When the voltage is applied to T621/1 SRT Input, current flows through
Changing the frequency of the switching regulates the output voltage at
the winding and R631 to Q621/G. Q621 Converter is a FET with added
the secondary winding comprised of T621/8 and 9. Taking a sample volt-
protection. When a positive voltage is applied to the gate, it begins to
age from T621/4 and applying it to rectifiers D624 and D625 does this. As
conduct drain to source. This reduces the voltage at T621/3 to close to
this voltage rises and falls, the rectified voltage is applied to Q622/B through
zero. Normally this would reduce the voltage at Q621/G, but a voltage is
R634. When Q622 begins to conduct, it lowers the voltage at Q621/G
supplied to the gate through R632 and C630 from T621/4. This voltage is
and changes the switching frequency.
induced into the secondary winding of T621/4 when current flows through
the winding between T621/1 and T621/3. The voltage is not permanent The changing frequency will change the amount of voltage coupled to the
due to C630. As C630 charges, it reduces the voltage at Q621/G. Once secondary winding consisting of T621/8 and 9. If the load on the second-
this voltage falls below a certain threshold, Q621 Converter turns OFF. ary output increases, the frequency of switching will decrease. This brings
the frequency of the converter closer to the optimum operating frequency
Once Q621 Converter turns OFF, all polarities are reversed. This rever-
of T621 SRT. Moving closer to this optimum frequency causes more
sal of polarity helps speed up turn OFF of Q621. D623, along with C631
voltage to be provided at T621/9. The opposite occurs when the load on
and R640, form a snubber network (voltage clamp). This network clamps
the supply decreases. This causes the frequency of operation to be in-
excessive voltage overshoot caused by the collapsing magnetic field of
creased and the amount of voltage coupled to T621/9 to be decreased.
T621 SRT and returns the excessive voltage to C629. When the field
The supply typically operates at 45 kHz when the set is OFF and at about
collapses fully, current begins to flow through T621/1 and 3.
30 kHz when the set is operating. The incoming line voltage also effects
the frequency of switching operation.
 T621
FB621 R639 SRT
D621 4.7 OHMS
1
D622 R640 C631
FROM TO RY600
2 11
T601/1 POWER RELAY
D623
AC Hi
SIDE 3 10

IC622
R631 5V REG
7.2VDC BAO5T
D
C630 R632 D628 CN641
4 9 I O 10
G
D624 STANDBY
S C650 +5V TO
Q621 D698 D625
A BOARD
2SK2845 CN1641
D699 R633
MTZ-T-77 C637
C633 TO Q646/E
-15 .
5 8 BACKUP
R634
R635
C634 D627
6
D626 R638
RD6.2ESB2
C629 Q622
PROT. C699
C636
C635
R636
FROM R637
R623 G BOARD
&R664 AC
Lo SIDE
3 CTV26 1187 12/28/99
STANDBY SUPPLY

10
 11

Over Current Protection (OCP) Secondary Output

Monitoring the voltage across R637 is used for over current protection. The power coupled through T621 SRT places a voltage on T621/9 that,
This voltage is representative of the amount of current flowing through when rectified and filtered by D628 and C637, is 7.2 volts. This voltage is
Q621 Converter since it is in series with the transistor. If this voltage constant due to the regulation circuit on the primary side of T621 SRT.
should rise to .6 volts, it will cause Q622 to turn ON. If Q622 were to turn This 7.2 volts is applied to Q646/E for backup during the start of regula-
ON, it would shunt Q621/G voltage to ground. This would cause Q621 tion by the regular power supply.
Converter to stop conducting. It is also applied to IC622 5-Volt Regulator, which regulates its output to 5
Over Voltage Protection (OVP) volts. This 5 volts is sent to CN641/10 which connects to the A board and
powers the Tuning Micon and other circuits. It is also applied to RY600
Over voltage protection is done by rectifying the voltage at T621/6 with
Power Relay.
D627. This voltage is filtered by C636 and applied to D626 through R638.
If this voltage should rise above 6.2 volts, D626 begins to conduct. When Checking Q621
its conduction allows Q622 Protect to turn ON, over voltage protection is Testing a MOSFET device is simple. The leads show infinite resistance
employed. Q622 Protect turns ON and grounds Q621/G, which stops the to each other except for drain to source in one direction because of the
converter from switching. presence of a protection diode.
D699 is also used for OVP. The signal from T621/4 is rectified by D698. To prove the device is functional:
This creates a negative voltage across C699. If this negative voltage
becomes great enough, D699 conducts and the Q621/G voltage is brought 1. Connect the negative lead of the ohmmeter to the SOURCE lead.
lower. 2. Touch the ohmmeter positive lead to the gate, to pre-charge it.
3. Connect the ohmmeter positive lead to the DRAIN. If the device is
good you will get a resistance reading of about 400-1k ohms.
Some DVMs do not produce enough DC voltage in the ohms mode. The
diode check mode can be used with these models. When using the diode
mode, a low voltage drop is shown after pre-charging the gate.
 T621
FB621 R639 SRT
D621 4.7 OHMS
1
D622 R640 C631
FROM TO RY600
2 11
T601/1 POWER RELAY
D623
AC Hi
SIDE 3 10

IC622
R631 5V REG
7.2VDC BAO5T
D
C630 R632 D628 CN641
4 9 I O 10
G
D624 STANDBY
S C650 +5V TO
Q621 D698 D625
A BOARD
2SK2845 CN1641
D699 R633
MTZ-T-77 C637
C633 TO Q646/E
-15 .
5 8 BACKUP
R634
R635
C634 D627
6
D626 R638
RD6.2ESB2
C629 Q622
PROT. C699
C636
C635
R636
FROM R637
R623 G BOARD
&R664 AC
Lo SIDE
3 CTV26 1187 12/28/99
STANDBY SUPPLY

12
 13

Power On/Degaussing Degaussing

When the set is turned ON, a click is heard from the Power Relay RY600.
About one second later another click is heard from RY601 Degauss Re-
Overview
lay. After this a loud hum can be heard. This indicates that the degauss-
This section discusses how the converter B+ voltage is created when the ing circuit is operating. The degaussing circuit operates because every
set is turned ON. When the set is turned ON, the degaussing circuit is time the set is turned ON, a HIGH is output from IC001/33 Tuning Micon
activated. O-HP SEL. This HIGH is applied via the cable between CN1641 on the A
Power On board and CN641 on the G board. This voltage is used to turn ON Q644.
When Q644 is turned ON, RY601 is energized, causing current to flow
When the set is plugged in, the AC voltage is applied through F601, T601 from the AC line through THP601 and THP602. When current flows,
and T602. Additional components C605, VDR601, C604 and VDR602 120VAC is applied to the degaussing coils. When this occurs, a hum can
are across the AC line input. They are in place for protection from AC line be heard.
spikes and surges. This AC voltage is applied to the standby power sup-
ply and will be applied to D602 Bridge Rectifier when RY600 Power Relay THP601 and THP602 are thermistors whose resistance increases as they
is closed. R623 and R664 will limit the current when the relay is initially get warmer. The thermistors should read less than 10 ohms when cold.
closed. The current flowing through them when voltage is applied to the degauss-
ing coils is great and causes the thermistors to open after a few seconds.
When the customer turns the set ON using either the remote or the power This stops the action of the degaussing coils since no more current is
switch, a 5-volt signal is output from IC001/62 Tuning Micon O-Relay. flowing through them. The set will not degauss properly if the set is turned
This HIGH is sent to the G board via the wiring harness between CN1641 OFF and ON again quickly. You typically need to wait at least a few
on A board and CN641 on the G board. minutes until the thermistors have cooled to degauss again.
This signal is used to turn Q648 ON. When Q648 turns ON, it places a If the degaussing circuit is not operating, no hum will be heard when the
LOW at its collector. This causes RY600 to energize, closing the contact set is turned ON. It is also likely that purity problems will occur since the
and allowing current to flow to D602 Bridge Rectifier. The LOW from tube could become magnetized.
Q648/C is also applied to the Q646 Backup and Q647 Soft Start transis-
tors. Room vibrations may cause the contacts of RY601 to make contact when
they are not supposed to, causing the degauss coils to be activated while
Voltage Doubler the set is producing a picture. If this occurs, the customer may complain
D602 Bridge Rectifier is used with C606, C607, D629 and D630 to form a about an intermittent rainbow pattern or intermittent loss of purity. If a
voltage doubler. Therefore, the output of the voltage doubler is approxi- customer complains about this, try replacing RY601.
mately 310 VDC. This voltage will be referred to as Converter B+. Con-
verter B+ is applied to the converter circuit through R607. R607 is a
fusible resistor. If the converter circuit draws too much current, it will
open. When RY600 Power Relay is closed, a click is heard. When the
Converter B+ is applied to the converter circuit, it will begin to operate and
supply power to the rest of the set.
 IC622
BAO5T TO
5V REG. CN641/10
R623 STANDBY STANDBY
R603 C603 5V
POWER I O
SUPPLY G
CN602 R664
T602 T601
1
2 3 4 3 4 RY600
R607
D602
CN603 F601 C605 VDR601 0.1 OHM
VDR602
1
C604 D629
6.3A TO
2 1 2 1 R625
DGC C607 CONVERTER

3
C606 D630
CN601 R624
1

DGC C601 RY601 HOT

THP602 GROUND
3
THP601
O-HPSEL
FROM Q644
CN641
IC001/33 VIA R642 12V TO
2 STANDBY Q646/B
CN1641/12 5V
A BD. R641 BACKUP
AND
R626 D614 Q647/B
O-RELAY 11 SOFT START
FROM C624
R622 Q648 RESET
IC001/62 VIA
CN1641/11 FROM
A BD. Q642/E G BOARD
LATCH

POWER ON/DEGAUSSING 4CTV26 1188 12/28/99

14
 15

Converter Soft Start

The voltage across T604/7 and 8 Control Winding determines the fre-
quency of operation. The control winding is a cross inductance winding.
Overview
At initial startup the converter has to switch above the optimum frequency
The function of the converter is to switch the Converter B+ voltage through of T605 PIT. A soft start circuit is used to ensure that this occurs. The
a transformer’s primary winding. This switching will produce a signal that soft start circuit will ensure that a voltage of approximately 7 volts will be
will be coupled to the transformers secondary windings where they are applied across T603/7 and 8 Control Winding. After the converter begins
rectified and used to supply various voltages to the set. The frequency of to run, the voltage from the Vcc Rect. line is applied to T603/8 through
this switching is controlled to maintain a consistent value on the +135 volt D612. The voltage applied to T603/7 will then come from the regulator
line. Changing the frequency of the switching can be used for regulation circuit instead of soft start.
due to the efficiency characteristics of the transformer. A second trans-
former with a cross-inductance winding is used to create a “dual tank Regulation
oscillator”. The voltage across the cross-inductance winding or control The frequency of the power supply is dependent on the load that it sees.
winding is used to change the value of the inductance in the tank circuit When the picture brightness increases, the load increases, lowering the
and consequently change the frequency of switching. voltage across T603/7 and 8. When this occurs, the frequency of the
oscillator decreases, allowing T605 to supply more current to the second-
Initial Start Up
ary windings. This keeps the 135V line from lowering in voltage.
When RY600 Power Relay (not shown) is closed, 300 VDC is developed
The following table shows what occurs with different loads on the supply.
and applied to R607. Converter B+ is then applied to C613 and C615.
Note that the oscillator frequency changed, but the 135V line remained
C613 ensures that the bottom transistor IC601-1 turns ON initially. When
within a few tenths of a volt of its value. You should also be aware that the
IC601-1 turns ON, there is a current path through C615, T605/1 and 2,
frequency of operation is also dependent on the input AC line voltage.
T603/1 and 2, through IC601-1/ C-E to ground. The voltage applied to
IC601-1/B by T603/4 sustains this current path. This voltage at T603/4 is
developed by the expanding magnetic field being produced by the current Location White Raster No Input
flowing through T603/1 and 2. When the magnetic field in T603 PRT V across pins 7 and 2.18 VDC 2.38 VDC
stops expanding, IC601-1 turns OFF. When this occurs, a voltage is 8/T603
induced by the collapsing magnetic field at T603/3 that turns IC601-2 ON. Freq. at IC601/E2 62 kHz 66 kHz
This provides a discharge path for C615. When C609 is fully charged, V at CN641/1 135.3 VDC 135.6 VDC
IC601-2 will turn OFF. This cycle will continue to repeat itself. As the
voltage across T604/7 and 8 Control Winding changes, the inductance of
the other windings will change. This will determine the frequency of switch-
ing.
 T605 11 +135V 1
PIT 2 TO A
10 +9V BOARD
6
+12V CN1641
1 9 8
SECONDARY CN641
2
8 SUPPLIES
AUDIO B+
3 1
C615
AUDIO 2
TO AK
4 7 GND. BOARD
3
CN1463
6 4
+5V
5
R607 R601 5
CN642

B+ TO PROTECTION
R615
310 V 120K D603 R602 D606/K
C618
R612 1 PRT
C613
120K T603
2

C609 C612
R608 3

C608
VCC RECT.
2
FB602 FROM
IC601 REGULATOR
R613 MX084 7
IC643/4
120K FB604 1 FROM
4 & SOFT
R614 8 SOFT START
120K C610 START Q645/E
D612 Q645B &
FOLDBACK Q624E FROM
BACK-UP
R611 C611
5 CONTROL Q646/E
WINDING

CONVERTER 2CTV26 1186 3/22/00

16
 17

Troubleshooting When performing this procedure, set your variac to zero. Jump the relay
contacts. Warning: By jumping the relay contacts you have defeated
One of the most common failures in switching power supplies are the
the protection circuitry of the power supply. Plug the unit into the
converter transistors or in the case of this power supply, IC601. IC601
variac and bring the AC voltage to 30 VAC. You should have stable oscil-
actually contains two identical transistors. They are assembled in this
lation at this point. Check to see how much current is being drawn from
package so that their gain and other characteristics are closely matched.
the AC line. The current drawn should be minimal since the supply is
Generally when these transistors fail, they fail by shorting C-E in one or
unloaded. Check the voltages at the points in the table below. The oscil-
both of the transistors. This causes the fusible resistor to open due to
lator voltage and frequency are measured at T603/2. The secondary
excessive current draw. The fusible resistor in this case is R607. The
voltages can be easily checked at CN641 and CN642. Increase the line
symptom in this set is that you hear only one relay click on initial power up
voltage by ten volts and check each item in the table again. Repeat this
instead of three. Usually you would hear two, the power relay followed by
procedure at 50 and 60 VAC. Warning: It is not recommended that the
the degaussing relay. This would be followed by another click about ten
power supply be operated unloaded above 60VAC.
seconds later that indicates the degaussing relay is turned OFF. You can
check the voltages around IC601 to troubleshoot this problem. There Another problem that may occur is that the switching never starts. To
would be no voltages present since R607 would be open due to the shorted troubleshoot this type of problem, remove one lead from C615. When
transistor. you power the set ON, you should have a DC voltage of half the Con-
verter B+ at T603/2. This is where the switching waveform would nor-
You should always check the horizontal output for shorts when the con-
mally be present. If the voltage is lower at this point, suspect an open
verter transistor has failed. It is also a good idea to unload the power
related to IC601-2 or a leaky component related to IC601-1. If the voltage
supply and bring the line voltage up slow using a variac.
is high at this point, suspect an open related to IC601-1 or a leaky compo-
nent related to IC601-2.

A A 2W C has sis P o w er S up p ly O u tp u t V o ltag es F u lly u n lo ade d (C N 641 and C N 642 un p lu gg ed )

P rim ary (H ot G round) S econda ry (C old G round )
V ariab le A C In p u t O scillator O scillator 135 12 9 5 A ud io
V oltage F re quency B+
30V ac 80 V p-p 145 kH z 48.7 V 14.5 V 5.0V -3.6V 4.5V
40V ac 100 V p-p 145 kH z 63.0 V 18.5 V 5.8V -3.7V 5.8V
50V ac 130 V p-p 147 kH z 63.2 V 20.0 V 6.3V -3.8V 6.1V
60V ac 150 V p-p U nstable 69.0 V 22.2 V 6.8V -3.8V 6.9V
 T605 11 +135V 1
PIT 2 TO A
10 +9V BOARD
6
+12V CN1641
1 9 8
SECONDARY CN641
2
8 SUPPLIES
AUDIO B+
3 1
C615
AUDIO 2
TO AK
4 7 GND. BOARD
3
CN1463
6 4
+5V
5
R607 R601 5
CN642

B+ TO PROTECTION
R615
310 V 120K D603 R602 D606/K
C618
R612 1 PRT
C613
120K T603
2

C609 C612
R608 3

C608
VCC RECT.
2
FB602 FROM
IC601 REGULATOR
R613 MX084 7
IC643/4
120K FB604 1 FROM
4 & SOFT
R614 8 SOFT START
120K C610 START Q645/E
D612 Q645B &
FOLDBACK Q624E FROM
BACK-UP
R611 C611
5 CONTROL Q646/E
WINDING

CONVERTER 2CTV26 1186 3/22/00

18
 19

Soft Start/Regulation/Foldback Regulation

The power supply is regulated by the control winding of PRT T603/7 and
8, in the following manner:
Overview
An increase in voltage across the control winding will reduce the induc-
The three circuits discussed here all have an affect on the voltages across
tance of the windings in T603, consequently increasing the converter fre-
T603/7 and 8. This winding of the PRT is a cross inductance winding or
quency. When the converter frequency increases, it moves further away
control winding that controls the frequency at which the converter oper-
from the optimum operating frequency of T605 PIT, reducing the voltage
ates.
at the secondary outputs. The opposite occurs when the voltage across
Soft Start pins 7 and 8 decreases. A correction voltage is produced by IC643/4,
At power ON, C602, which is discharged, has a 0V potential at its + termi- which varies inversely proportional to the 135V line. Pin 7 of the trans-
nal. This biases Q645 ON, via R647. With this transistor ON, it allows the former control winding is connected to the correction voltage. The other
standby unregulated from Q646/E to be applied across T603/7 and 8. leg of the control winding (pin 8) is connected to the output from D603 Vcc
This voltage is passed through Q646 Backup since the same line that Rectifier. The difference in the voltage across this winding determines
turns RY600 Power Relay ON turns it ON. The greater the voltage across the frequency of the converter which regulates the +135 Volt line as de-
this winding, the higher the converter frequency and the lower the effi- scribed in the previous sections.
ciency of T605 PIT. This is discussed in the Converter section. There- Foldback
fore, the start up secondary voltages will be reduced considerably. As
The foldback circuit is a type of protection circuit that uses a winding on
C602 charges, the voltage difference between T603/7 and 8 diminishes.
T605 PIT to monitor the current drawn by its secondary. This voltage is
As this voltage lowers, the secondary voltages will rise. When the Vcc
rectified and called Vcc Rect. Q624 is set up with the Vcc Rectifier volt-
Rectifier voltage is larger than the Standby unregulated voltage, D612 will
age input to the emitter. Its base is connected to the Rectified +12 volt
begin to conduct and the Vcc Rectifier voltage will control T603/8. Also at
line from the secondary side of the supply through D605 and R609. D605
this time C602 will be fully charged and IC643 Control IC will take control
is a zener diode whose breakover voltage is 13 volts.
over T603/7. The difference in voltage between T603/7 and 8 will regu-
late the converters operating frequency. This circuit will protect against two failures. The first is a rise in the Vcc
Soft Start Reset Rect. This voltage is developed by the foldback winding of T605. This
It is important that the soft start capacitor C602 be fully discharged when winding is used as a current mirror. This means that the more current
the set is turned OFF. Turning Q648 OFF when the unit is turned OFF drawn on the secondary of T605 PIT, the higher the voltage at T605/3.
does this. This removes the ground path from the relay, opening it up. It When too much current is drawn from the secondary, Q624 would turn
also allows current from the Standby +5V to flow through the relay coil, ON because of the increase in voltage across R610. If this occurs, the
through R621, to Q647/B. This turns the Q647 ON and discharges C602 latch and soft start circuits will be activated. Soft start is activated to lower
through R627. the output supply voltage by increasing the switching frequency. The
latch’s purpose is to shut the supply down.
Q646 Backup will also be turned OFF when the Power On line becomes
HIGH. Secondly, if there were a loss of the +12 volt line then D605 would
breakover. This would cause sufficient current flow through R610 and
Q624 would turn ON. If this occurs, the latch and soft start circuits will be
activated.
 STANDBY
+5V
5 PART OF
IC643
135V RY600
DM-58 R658
FROM R661
1
CONTROL 4 7
D643 IC
B+ C652 R659
8
RECTIFIER R648 R647 D612
3
R649 C651 Q645
R627 Q647 T603 PRT
CONTROL
C602 R665 WINDING

G BOARD

POWER
R699 TO
ON Q648 L=ON R621
D614 Q653/B
FROM R626
LATCH
CN641/11 R620
C624 R622 D606
RD24ESB2
D605 R619 OVP
+12V FROM MTZJ-T-
D651C & 7713A R609 Q624
D652C TO D607
R610
R602 PROTECT.
R601 D603
4 3

C618 Q646
PART OF D613
T605 PIT R618

STANDBY
UNREG FROM
D628/k

SOFT START/FOLDBACK/ REGULATION 5CTV26 1189 1/4/00

20
 21
The voltage is 9.6 instead of 9 because D647 is connected between the
Secondary Voltages ground pin of IC641 9 Volt Regulator and ground.
+9 Volt Protection
+135 Volts
The +9 volt line also is monitored for OCP. Using the voltage drop across
The signal from the winding of T605/10 and 11 is applied across D643 R680, R681 and R644 to control the conduction of Q649 does this. When
Bridge Rectifier and C643 and L642 filter the rectified voltage. D648 is a the amount of current drawn on the 9 volt line is sufficient to cause Q649
150-volt zener diode that will limit the voltage to 150 volts in case of a to conduct, Q650 will be turned ON. This places a LOW on the inhibit line
failure that causes the B+ to rise. This voltage is then sent through R652 of IC641 9 Volt Regulator. When there is a LOW present at this pin, the
and output from the G board at CN641/1 and 2. The voltage is used on output of IC641 is disabled.
the G board by the protection and regulation circuits and is also used to
produce the +33 volt line on the A board. +5 Volts
+12 Volts The +5 volt line will not be discussed since it is not used in the set.

D651 and D652 rectify the signal from T605/7 and 8. This voltage is Audio B+
filtered by C658 and input to IC650 12-Volt Regulator. IC650 outputs a The signal from T605/5 and 6 is applied to D641 Bridge Rectifier. The
regulated 12 volts that is filtered by C661 and output from the G board at negative side of D641 is connected through R643 to ground; therefore the
CN641/8. Audio B+ floats slightly above ground level. The voltage output from D641
+9 Volts is filtered by C641 and then sent to CN642/1 and 2 unregulated. The
audio B+ is used only by the Audio Output Amplifier IC1461 located on
The signal from T605/7 and 8 is applied to D642 through two similar par- the AK board. One step in troubleshooting a set that is shut down is to
allel networks consisting of L650 and R670, and L651 and R670. This disconnect CN642. If the set still operates, then replace IC1461 Audio
rectified voltage is then applied to the input of IC641 9-Volt Regulator. Output. Be sure to discharge the voltage at CN642/1 and 2 before reat-
The output of this IC outputs 9.6 volts to L652 and also to CN641/6 and 7. taching the connector to CN642.

Shorted Supply Distribution

+135 A Board - T503 Flyback, H Drive Q501, H Out Q502, Pin Amp Q512, WA board VM Drive Q946
+12 A Board - Q301 HP Buffer, IC353 SHP, All WA board except VM Drive
+9 A board - TU102 Tuner, IC351 VM Mute, IC352 YUV Switch, IC354 YUV Switch, IC355 Y/C Jungle, IC101 D/A
Converter, AK Board - IC1401 Audio Processor, IC1403 SRS, Q1102 Tuner 5 Volt Regulator, C Board - Q1790 IK
Buffer, UY Board - IC2006 5 Volt Regulator, IC3302 5 Volt Regulator, IC3304 Chroma Decoder, IC3308 YUV Switch,
UY Board IC2005 3.3 Volt Regulator, IC2006 5 Volt Regulator for tuners,
UY5 from IC2006 IC3504 Comb Filter
UY5 from IC3302 IC3307 V Chip, IC3303 PIP Processor
Audio B+ (33 AK Board - IC1461 Audio Output
volts)
 TO B+ OCP
TO D653 OCP
D643 Q651/E
& IC643 FOR
11
R652 REGULATION
C697 C696 L642
1 B+
FROM C698 C695
D648 C653 2 B+
C615 10 C643 EZO150AV1
CONVERTER
1 9
TO
D652 IC650
FROM 2 12V A BD.
T601/1
8 BA12T 0 8
CN641
C658 I C661
PRT 12V REG
7 G
D651 Q650 6
9V
6 7
TO D605
5 FOLDBACK R645 C662 R650 R646 CN641

Q649 R644
T603 PIT L650 IC641
R681 PQ09RF21
R670 9V REG L652

R680
I G 0
R651 C665
L651 D647 C647
D642 IC651
1 BAO5T 2 5 5V
5V REG NOT USED
R670
D641 3 C644
TO
+33 VOLTS
2 AU AK BD.
C641 1 B+ CN
4 1463

R643 AU
-E
CN642 3

SECONDARY SUPPLIES 6CTV26 1190 12 22 99

22
 23
Flyback Secondary Voltages Distribution The +12 volt line is derived from the signal at T503/9. It is sent through
The following voltages are scan derived. This means that some windings R537 and rectified by D531. In the event that a short occurs on this line,
of the flyback transformer have their signals rectified to create additional R537 may open. Since the vertical output is supplied by this line, R537
power supply lines: should always be checked if a vertical output failure is suspected.

ƒ 200 Volts C Board IC1701 CRT Amp The -15 volt line is derived from the signal at T503/7. It is sent through
ƒ +12 Volts A Board IC501 Pin Control, IC561 V Out R536 and rectified by D530. In the event that a short occurs on this line,
ƒ -15 Volts IC501 Pin Control, IC561 V Out, Q511 Pin Drive, WA Board R536 may open. Since the vertical output is supplied by this line, R536
IC961 N/S Amp should always be checked if a vertical output failure is suspected.
The scan-derived supplies are developed when the output from Q502 H In addition to the scan derived supply voltages, T503 Flyback Transformer
Out is input to T503 Flyback Transformer. This signal is used to create also develops heater voltage from T503/5. T503 also develops high volt-
the boosted B+ (+200) on the primary side and the +12 and –15 volts on age, focus voltage and ABL.
the secondary side. The signal from T503/4 is sent through R553 and
rectified by D534. This voltage is output from CN503/5 on the A board to
CN503 on the C board. This voltage is used to supply IC1761 CRT Amp
on the C board. This connector can be disconnected to check to see if the
problem is with IC1761 CRT Amp. PART OF
T503
FLYBACK

FROM
Q502/C 1
H OUT

B+ 2

9 +12V To A Board IC501 Pin Control, IC561 V Out

6
R537 D531
8

7 -15V To IC501 Pin Control, IC561 V Out, Q511 Pin Drive, WA

Board, IC961 N/S Amp
R536 D530

TO H
PROTECT
1
TO CN503
R553 D534 C BOARD
5
C541 R538
CN503

SCAN DERIVED SUPPLIES 9CTV26 1/4/00

The table below describes various symptoms that can occur if there is a Many times observing all the symptoms can lead you towards the correct
short on any of the power supply lines. These types of problems occur failed component or problem. All of your senses should be used when
when major components being supplied fail by shorting. An example troubleshooting. What you see, hear and smell can often lead you to
would be if the audio amp were to fail the set might shut down as if the quick fix.
Audio B+ line were shorted.

Voltage Relay Clicks Video Audio Timer HV Power Switch OFF Suspect
LED
+135 * 2 clicks very close None None Blinking None No relay click but Q502 H Out, T503
together Power Only Timer LED stops Flyback, Q512 Pin
blinking Out
+12 1 click. Power relay IK lines visible. OK Normal OK Unit shuts off WA board problem
only. OSD expanded normally. or Q301 or IC353 on
almost off screen A Board
+9 2 clicks Power Relay None None Blinking None Both relays turn Regulators on A
and Degauss relay. OFF and Timer LED board .
Degauss relay never stops blinking.
turns OFF
Audio Normal Normal None Normal Normal Normal PS1461 AK Board
B+**
+200 2 clicks very close None None Blinking None No relay click but IC1761 CRT Amp.
together Power Only Timer LED stops Disconnect CN1764
blinking to verify.
+12 3 clicks. 2 Normal but None None Blinking None No clicks. IC561 Vertical
then an extra click Output. Check
indicating shutdown. R537.
-15 2 clicks. Power and None None Blinking Starts to come 2 clicks when set is IC561 Vertical
Degauss up but stops turned OFF. Output. Check
after 2nd click R536
Converter 1 click. Power Relay None None Blinking None 1 click. Power Relay IC601 and/or R607
not only. only.
switching

* May cause the IC601 Converter to fail. **May cause shutdown similar to
+135 if fuse doesn’t blow.

24
 25

Power Supply Protection Foldback

The foldback circuit is a type of protection circuit that uses a winding on
T605 PIT to monitor the current drawn by its secondary. This voltage is
Overview
rectified and called Vcc Rect. Q624 is set up with the Vcc Rectifier volt-
There are three different circuits that can activate the protection latch. age input to the emitter. Its base is connected to the Rectified +12 volt
One is the OCP (Over Current Protection) for the +135 volt line. The other line from the secondary side of the supply, through D605 and R609. D605
two are related to the voltage from T605/3 Foldback Winding. When one is a zener diode whose breakover voltage is 13 volts.
of these circuits activates the latch, RY600 is turned OFF. This discon-
This circuit will protect against two failures. The first is a rise in the Vcc
nects the AC from the circuit that develops Converter B+ and can be
Rect. This voltage is developed by the foldback winding of T605. This
noticed during troubleshooting when two clicks are heard in quick succes-
winding is used as a current mirror. This means that the more current
sion.
drawn on the secondary of T605 PIT, the higher the voltage at T605/3.
Latch When too much current is drawn from the secondary, Q624 would turn
Placing a HIGH on Q653/B activates the latch. This turns ON Q653 that ON because of the increase in voltage across R610. If this occurs, the
turns ON Q652. Once Q652 turns ON, its conduction keeps Q653 ON latch and soft start circuits will be activated. Soft start is activated to lower
until power is disconnected. This places a LOW at Q648/B, turning it the output supply voltage by increasing the switching frequency. The
OFF. This causes RY600 Power Relay to open and the set turns OFF. latch’s purpose is to shut the supply down.
Secondly, if there were a loss of the +12 volt line then D605 would
+135 Over Current Protection breakover. This would cause sufficient current flow through R610 and
Over current is detected by monitoring the voltage across R652. When Q624 would turn ON. If this occurs, the latch and soft start circuits will be
this voltage, which rises as more current is drawn, gets to a level that activated.
causes Q651 to turn ON, the latch will be activated.
Vcc Rectified Low Voltage Protect (LVP)
The signal from T605/3 is sent through R601 and rectified by D603. This
voltage is filtered by C618. It is important that this voltage be at a certain
level since it is used to control regulation. Therefore a circuit is con-
structed in which Q623 is normally ON. This transistor is ON because
D607 should always have sufficient bias to turn ON. This will place Q623/
C at close to ground level. This keeps D604 and D608 from conducting
and activating the latch circuit. If this voltage were to fall below a certain
level, D607 would turn OFF, causing Q623 to turn OFF. When Q623 is
OFF, the +12 volt line would cause D604 and D608 to turn ON, activating
the latch.
 TO CN641/1
R652 B+
B+
135V D648
EZO150AVI R653 D653
OVP +12V

R654 C656
R606
C614 Q651
PART OF VCC RECT.
T605PIT Q623 D604 OCP
R601 D603 R663
3
D608 R655 R662
D607 RD6.8ESB2
R602 RD6.8ESB2
C618 R605
NORMALLY TO Q648
4
ON
POWER ON

POWER
ON FROM
Q652 CN641/11
R610
R657

LATCH
R699
Q653
Q624 D606
FOLDBACK C657 R656
R609 RD24ESD2
TO D612
D605
CONVERTER
MTZJ-T-77
REGULATION
13A
FROM
+12V TO SOFT
START RESET
R665 Q647/B

POWER SUPPLY PROTECTION 1CTV26 1185 3/22/00

26
 27
These pulses keep Q652 ON and prevents C563 from charging. There-
Vertical Deflection fore Q561 is always OFF while the set is operating normally. If the verti-
cal flyback pulses were missing, the voltage from the 12-volt line through
The vertical deflection stage consists of the Vertical oscillator, Vertical R570 would forward bias Q561 B-E. This would apply a low to IC355/15
amplifier, Flyback generator and the Deflection yoke. VM Out/V Protect. If IC355/15 were to receive a LOW, the IC would blank
The purpose of this stage is to manufacture a magnetic field. The the video. If there were problems in this area when the unit is initially
magnetic field will bring the electron beam gradually from top to bottom turned ON, the result would be similar to an AKB problem. The degauss
(vertically) and then quickly back to the top (beam retrace) of the screen relay would not turn OFF and the Timer LED would be flashing.
to start over again. Deflection yoke
Vertical Oscillator The deflection yoke translates the electrical current flowing through its
When the TV is turned ON, Set +9Vdc appears at Y/C Jungle IC301/33 coils into a magnetic field that positions the election beam vertically.
and 44. The internal horizontal oscillator begins and is counted down Current flowing through the deflection yoke coil is returned to ground
(divided) to 60 Hz to become the vertical drive signal. through R578, R563 and R559 and TH501, which are in series. The
thermistor is used for temperature compensation. As the vertical yoke
The drive signal is formed into a positive and negative ramp and its
draws more current, the resistance of TH501 lowers, allowing more
amplitude and linearity are determined by the serial data from IC001
current to flow to the yokes. The voltage developed across these
Tuning Micon. If the data or clock signal at IC355/34 and 35 were
resistors is fed back to the inverting input of IC561/1 through R566 to
missing, there would be NO vertical drive at IC301/13 and 14.
improve linearity.
Vertical Amplifier
IC561 Vertical Output is a single package vertical amplifier that outputs
a waveform with sufficient amplitude and current to drive the deflection
yoke. It is powered by +12 and –15 volts from the flyback transformer
secondary.
Flyback / Boost Generator IC355/13 - 1V, 5ms
IC355/14 - 1V, 5ms

The vertical boost signal is used to generate extra current in the deflec-
tion yoke during the retrace period. This extra current is used to quickly
return the electron beam to the top of the picture.
The flyback generator stage within IC561 uses the vertical signal to
make a 30Vp-p pulse needed during retrace time. The retrace portion
of the vertical drive signal input IC561/1 and 7 is extracted and ampli- IC561/5 - 20V, 5ms IC561/3 - 20V, 5ms
fied, and appears at pin 3 as a 30Vp-p pulse. It passes through C565
to provide sufficient current to power IC561/6 during retrace time.
Diode D561 blocks this pulse from the +12 volt source.
The vertical flyback pulse from IC561/3 is sent to the WA board to be
used by the Quadra Pole Focus circuit. It is also goes to C564. C654
blocks any DC and allows the flyback pulses to be applied to Q652/B. Q562/B - .5V, 5ms CN501/5 - 1V, 5ms
 2
TO WA
D388 BOARD
+12V SCAN MTZJ11B C565 CN942
D561
DERIVED 1
SUPPLY R537 D531 +12V
CN1942
FROM T503/8 C564
R570 Q561
Q562
R573
R571 C563
R572
+9V
2 6 3 TO IC355/15
SCL VM OUT/
IC561
SDA STV9379 V PROTECT
VERT.OUT FLYBACK
35 34 33 44 R569 GENERATOR
13 7 + DY
VD+ R384
R568 5 6
VD- 14 1 -
R387 R561
4
IC355 R566 -15v
CXA2131S D384 R567 C568 R585
Y/C/J 5
MTZJ11B
CN501
R559
VTIM R563
5 R578 TH501
-15V SCAN
DERIVED R536 D530
MAIN A BOARD
SUPPLY
VP FROM T503/7

VERTICAL DEFLECTION 10CTV26 1194 1/4/00

28
 29

Failure Relay Clicks Video Audio Timer LED HV Power

Switch OFF
Open Two clicks. None Normal Flashing Normal Two clicks.
Yoke Degauss never turns Power and
OFF. degauss
relays as
normal.
Short on Two normal clicks, No video for 30 seconds, Normal Flashing for Normal Two clicks.
Output but third click then flashing horizontal line first 30 Power and
(degauss) isn t across the screen. Line is seconds then degauss
heard for 30 about 1 inch thick. stops. relays as
seconds. normal.
+Missing Three relay clicks, None Normal Not flashing Normal Two clicks.
data or Power Relay, Power and
clock degauss and then degauss
degauss again relays as
Second degauss normal.
click occurs quicker
than normal
Missing Three relay clicks. None May or may not be Flashing. Comes up No click.
Scan Two are normal, heard before until
derived third is shutdown. shutdown shutdown.
+12 volts
Missing Two clicks - Power None May or may not be Flashing. Normal. Two clicks.
Scan and Degauss relays. heard before Power and
derived shutdown degauss
15 volts relays as
normal.
Shorted Normal three clicks Yes but there are two red Normal Normal. Normal Two clicks.
or open green and blue lines each in Flashes until Power and
C565 the top half of the picture. If picture is degauss
video is input, these lines displayed relays as
remain and white retrace normal.
lines are seen in the top
 2
TO WA
D388 BOARD
+12V SCAN MTZJ11B C565 CN942
D561
DERIVED 1
SUPPLY R537 D531 +12V
CN1942
FROM T503/8 C564
R570 Q561
Q562
R573
R571 C563
R572
+9V
2 6 3 TO IC355/15
SCL VM OUT/
IC561
SDA STV9379 V PROTECT
VERT.OUT FLYBACK
35 34 33 44 R569 GENERATOR
13 7 + DY
VD+ R384
R568 5 6
VD- 14 1 -
R387 R561
4
IC355 R566 -15v
CXA2131S D384 R567 C568 R585
Y/C/J 5
MTZJ11B
CN501
R559
VTIM R563
5 R578 TH501
-15V SCAN
DERIVED R536 D530
MAIN A BOARD
SUPPLY
VP FROM T503/7

VERTICAL DEFLECTION 10CTV26 1194 1/4/00

30
 31
The purpose of the pincushion circuit is to correct for deflection distortion,
Horizontal Deflection Block which occurs because of the yoke’s inability to create a linear beam scan.
The result would be a picture bowed at the sides. We compensate for this
Overview problem by using pincushion correction circuits to control the amount of
The horizontal deflection block creates the signal that drives the horizon- current that can flow through the horizontal output’s return.
tal yoke and also drives the flyback transformer to create the necessary More current is delivered so the beam can be pushed to the sides of the
high voltage, focus voltage and other voltages used by the set. tube when necessary. The drive for the Pin amp is created in the Y/C/J
The HD signal originates from the Y/C/J. The HD signal is applied to the and is called E/W drive. It is applied to the Pin amp with a sample of the
amplifiers in the H drive and H Out circuits. The signal that exits the H Out HP pulse. Q512 controls the current through the H Out return.
transistor is applied to the flyback transformer and the deflection yoke. A protection circuit also monitors the HP signal. This protection circuit
The deflection yoke uses magnetic fields formed by the current through it allows HP signals to pass to the Y/C/J if the Pin amp and H Out circuits
to drive the beam across the screen. Feedback from the yoke is coupled are operating normally. In the event of a failure, the HP/Hoff line to the Y/
to the centering and linearity circuits. This circuit ensures that the picture C/J would go LOW. The Y/C/J would then disable HD, which would cause
will be linear and centered properly. These circuits work in conjunction high voltage to be lost.
with the pin amp on the return to the H Out.
 HP
ABL

G2
HD
Q501 Q501 T503 HV
H DRIVE H OUT FLYBACK FV
SCAN +200
DERIVED +12
Y/C/J
SUPPLIES -15
IC355

E/W DRIVE Q512

PIN AMP DY

CENTERING
+
LINEARITY

HP/H OFF
H PROTECT

HORIZONTAL DEFLECTION BLOCK 14CTV26 01/01/00

32
 33
Horizontal Output
Horizontal Out
Q502 is the H output transistor and it drives two circuits:
Overview • The deflection yoke – Develops a magnetic field in order to move the
electron beam from left to right on the screen.
The horizontal output circuit below consists of the Horizontal Oscillator, • The flyback transformers – Develops high, focus and screen voltages.
Horizontal Drive, Horizontal Output, Flyback and Horizontal Centering and The scan derived power supplies are also developed here. They are
Linearity. +200 volts, +12 volts and –15 volts for the CRT Amp and TV’s vertical
Horizontal Oscillator section. Heater voltage for the tube’s filament is also developed here.
When the TV is turned ON, Set +9Vdc appears and is applied to Y/C The horizontal protection circuit also uses the heater voltage.
Jungle IC355/33 and 44. IC355 contains a horizontal oscillator that is The HP pulse is fed back to monitor the frequency of the horizontal oscil-
shaped into a horizontal drive pulse that leaves at pin 19. lator. The horizontal output is also modulated by Q512 Pin Out. This is
necessary to correct for pincushion distortion that would be seen if cor-
rection were not used.

Q501/B - .5V, 20us

Horizontal Drive C510 - 10V, 20us CN501/3 - 50V, 20us

Q501 amplifies this HD signal and outputs the signal from its collector.
This signal is coupled by T501 to drive the horizontal output Q502 B-E
junction.
Horizontal Centering and Linearity
Changing the DC voltage at the return line of the horizontal yoke performs
horizontal Centering. The +135 volt line is switched through a series of
voltage dividers using S501 and S502. The different combination of switch
settings changes the DC level at the yoke return and, consequently, the
centering of the picture.
Horizontal linearity is determined by feeding back the yoke return signal
through an elaborate filter network, which is made up of T505 and its
Q502/B - 10V, 20us associated components to reference of the horizontal output.
 +9V
+9V
B+
135V

33 44 R385
R504 MAIN
R383 HP
HD 19 R552 T503 1/2
T501 FLYBACK
TO 2nd.
IC355 R539 HDT Q502
ANODE
CXA2131S R513 HV
1 6
Y/C/J C502 C507
D502 SV
Q501 C509 G2
R501 R507
3 4 C554 D503 200V FV
C527
TO C
C503 R503
R502 C505 C510 BOARD
B+ 11
FROM C504 C511
135V ABL
PIN
OUT B+
Q512 +135V D504 C1501 C514
C513
L503 1

4 2 1 4 2

C518 T502 DY
L501 T505 PMT 3

HLT 2 1 10 7 4
R576 S501 H
L505 CN501
CENTERING
S502 H
CENTERING R509 C553
R511 R512
JW R520 C516
C515 R510
D506
D505 C517 L502

H OUT 11CTV26 1193 12/22/99

34
 35
This signal is then applied to the base of Q511 Pin Out. The signal is
Pincushion inverted by Q511 and then input to the base of Q512. The result is that a
PWM waveform is seen at Q512/C. Q512/C is connected to the return for
Overview the horizontal output. When Q512 Pin Out is conducting it allows more
The purpose of the pincushion circuit is to correct for deflection distortion. current to be drawn by the horizontal yoke. The conduction of Q512 is set
This distortion occurs because of the yokes inability to create a linear up so that more current is drawn during the middle edges of the scanning
beam scan. The result would be a picture bowed at the sides. We com- of a horizontal line. The result is shown where the output leaves this
pensate for this problem by using pincushion correction circuits to control circuit at R526.
the amount of current that can flow through the horizontal output’s return. The H Protect circuit will remove the horizontal drive signal if the HP pulses
More current is delivered so the beam can be pushed to the sides of the are not input to IC501/5. This will also occur if Q511 or Q512 short.
tube when necessary.
Circuit Description
The E/W signal from IC355/11 is input to IC501 Pin Control at its inverting
input. A sample of the ABL signal from T503/11 is also input to this same
input.
The main HP signal from C510 in the Horizontal Output section is applied
to R524. The signal is applied to a clamp that consists of D518, D523 and Q512/B - 2V, 5ms Q512/C - 50V, 20us
D524. It is also applied to R525 and D516. This signal is now stripped of
its negative component and integrated by C530. This signal is then ap-
plied to IC501/5 non-inverting input. IC501 Pin Control compares the
inverting and non-inverting inputs and outputs their difference. The result
is output at IC501/7.

R526 - 100V, 5ms

IC501/5 - .5V, 20us IC501/6 - .2V, 5ms

IC501/7 - .5V, 5ms

ABL
FROM T503/11 TO Q504
NECK
E/W
B+ PROTECT
FROM IC355/11
+135V
R540
R515 C520 R506
FROM C510
MAIN HP R581
C521
C519
R526 TO H
D536 D535 R523
R327 OUT
D515 L511
R524 C522 C525 DWG.

C528
R517
R525 R516
6 - R518 R519 Q512
7
D516 PIN
5 + Q511 OUT
PIN
IC501 DRIVE
R528 C530 1/2 C526
D518 +12V
-15V -15V B+
D523
135V
MTZJ-T-
77-3.6
D524 C529
MTZJ-T-
77-6.8

12CTV26 1/1/00
PINCUSHION

36
 37
IC501/2 is also connected to Q503/C. Q503 is OFF as long as the signal
H Protect from the Pin Out circuit is working normally. If the Pin Out signal were
missing, Q504, which is normally ON, would turn OFF. If Q504 were to
Overview turn OFF, Q503 would turn ON. This would place IC501/2 at ground
The H protect circuit is used to shut down the horizontal deflection circuit potential. In that case, IC501/1 would output +12 volts that would turn
if the high voltage should rise above the acceptable level or if the pincush- Q301 ON and ground the HP signal that is connected to Q301. If Q301
ion drive circuit. Pulses from the flyback transformer’s heater winding are turns ON, IC355 would shut OFF the drive signal at IC355/19 HD. When
compared against a reference voltage. The reference voltage can be the drive signal is removed, the High Voltage is removed from the set.
removed based on the condition of the Pin Out circuit. Loss of Pin Out will This will cause a no video condition, but the Timer LED will not begin to
cause horizontal protection to be indicated. When H protect is detected, blink. If the set is turned on with a failure that causes H protect to occur,
HP pulses will be removed from IC355/19 HP/Hoff. Video and HV will be High Voltage would begin to come up and then disappear. The timer LED
disabled, but the power supply will continue to function. would blink to indicate that the AKB circuit did not unblank the video. The
Timer LED only indicates an AKB failure when the set is turned from OFF
Circuit Description to ON.
When the horizontal circuit is operating normally, a signal is output from
T503/5 that is used to supply voltage to the filaments of the tube. At this
point R550, R529, C531 and C532 filter the signal to a DC voltage. This
DC voltage is input to IC501/3 non-inverting input. This voltage is com-
pared to a reference voltage of 8.2 volts. This reference voltage is derived
by a voltage divider consisting of R533, D520 and D521. As long as
IC501/2 is greater than IC501/3, the horizontal circuit is operating nor-
mally.
 B+ +12V FROM
+12V 135V C510 HP

R539
R527 R533 IC355
NORMALLY IC501 2/2 CXA2131S
D530 Y/C/J
ON Q503
FROM Q504 8.2V R361 Q301
Q512/C R544
2 - 18 HP/PRM
1
PIN 3 + R356 19 HD
C549 C548 D302
OUT R514
R521 C543 TO Q501
D521 H DRIVE
MTZJ-7-5X
R532

8V
FROM R550 R529
T503/5
FLYBACK +
HEATER C531 R531 R530 D522 R531
C532

CN503 1 1 CN1103
TO C CHECK
BOARD CONNECTOR
CN1764

H PROTECT 13CTV26 1195 1/4/00

38
S CONFIDENTIAL csv-1
Sony Service Company
National Technical Services Service Bulletin
A Division of Sony Electronics Inc.
Park Ridge, New Jersey 07656 TV Products
Model: KV-27FV15
No. 412

Date: October 1, 1999

Subject: Part Number Correction
Reference No. 4, A Board

Symptom:
(XXXX) The part number listed on page 66 of the Service Manual for Ref # 4, A Board, is
incorrect.

Solution: Please note the correct part number as shown below.

REF DESCRIPTION PART NUMBER

INCORRECT CORRECT
4 A BOARD A-1298-866-A A-1298-886-A

I
The part number is listed correctly on page 69

Reference: FPR-U0879 PRINTED IN USA

 S CONFIDENTIAL csv-1
Sony Service Company
National Technical Services Service Bulletin
A Division of Sony Electronics Inc.
Park Ridge, New Jersey 07656 TV Products
Model: KV-36FS10, KV-36FV15, KV-36XBR250
SU-36FD2 No. 415

Date: October 1, 1999

Subject: Glass Stand Door rubbing on bottom of
cabinet

Symptom:
(161X) Glass doors, of the SU-36FD2 stand, rubbing on bottom board, Glass door scraping
off vinyl on bottom board, and bowing of bottom board when unit is positioned on high
pile carpet.

Solution: If the customer should complain of the symptoms above please do the following:

Service Part Kit 4-074-400-01

1. Order the Service Part Kit See Fig 1

II

Fig 1

2. Use the Jig Screw to remove the original pivot by inserting the screw into the
pivot hole and pulling down. See Fig 2

Fig 2

Reference: ECN KVC01816 PRINTED IN USA

Replace the Pivot on the top of the Glass Doors, and add the washer to the
bottom pivots. See Fig 3.

Fig 3

III
 S CONFIDENTIAL
Sony Service Company
National Technical Services Service Bulletin csv-1
A Division of Sony Electronics Inc.
Park Ridge, New Jersey 07656 TV Products
Model: KV-27FV15, KV-32FS10, KV-32FV15
KV-32XBR250, KV-36FS10, KV-36FV15 No. 417
KV-36XBR250

Date: October 7, 1999

Subject: Blinking Picture With Local Weather Channel

Symptom:
(2314) On the Weather Channel when the program switches from the national to local
weather the picture may, jump, blink, or may blank out.

Solution: If the customer should complain about the symptoms above then please
check in the Service Mode that VSS=1. If not change VSS to 1 and recheck to verify
if the problem is solved

if the symptom is still present then change the jungle IC355, on the A Board, with
the new type below. The adjustments for Vertical, Horizontal, Color, and Hue will also
needed to be re-adjusted.

Ref Old New Part Number

IV

IC355 CXA2131S CXA2131AS T-998-606-67

Reference: M.Matsuoka FPR: U0828 PRINTED IN USA

S CONFIDENTIAL csv-1
Sony Service Company
National Technical Services Service Bulletin
A Division of Sony Electronics Inc.
Park Ridge, New Jersey 07656 TV Products
Model: KV-27FV15, KV-32FS10, KV-36FS10
KV-32FV15, KV-36FV15, KV-32XBR250 No. 422
KV-36XBR250

Date: September 20, 1999

Subject: G Board Schematic Correction

Symptom:
(xxxx) On the G Board Schematic the winding connections inside T605 is incorrect.
The windings between T605/pins 1 & 2, and windings 3 & 4 are missing.

Solution: Please refer to the corrected schematic below. The proper connections have a
winding between T605/pin 1 & 2, and T605/pin 3 & 4. There is no winding between
T605/pins 2 & 3 as in the service manual schematic

Reference: FPR-U0789 PRINTED IN USA

 S CONFIDENTIAL csv-1
Sony Service Company
National Technical Services Service Bulletin
A Division of Sony Electronics Inc.
Park Ridge, New Jersey 07656 TV Products
Model: KV-32FS10, KV-32FV15, KV-36FS10
KV-36FV15, KV-32XBR250, KV-36XBR250 No. 424

Date: October 7, 1999

Subject: V Bow and H Trap Adjustments

Symptom:
(xxxx) V Bow and H Trap Adjustments are missing from the Service Manual

Solution: If the customer complains of poor geometry, (trapezoidal or bowing) the following
adjustments might be needed.

V-Bow Geometry distortion; like the picture in Fig 1 can be readjusted by using
the Y-Magnets. The Y-Magnet is located on the Neck Assembly CRT side See Fig 3.
VI

Fig. 1. Before Fig. 2. After

Y Magnets located
on the Neck
Assembly

A djust the taps simultaneously to achieve the best geometry. After adjusting this magnet, please confirm the
over all geometry again. (V-Trap, etc could also affect the geometry as well.)

Reference: Tomohiro Mori PRINTED IN USA

Adjust the taps simultaneously to achieve the best geometry. After adjusting this magnet, please confirm the over all
geometry again. (V-Trap, etc could also affect the geometry as well.)
H Trap Distortion:

If H-Trapezoid geometry is present, you can adjust the H trap (RV941) on the
WA Board. (See Fig 4)

After adjusting check the overall geometry again since V Bow can also affect the
Trapezoid distortion.

RV941

H-Trap WA Board RV941

VII
 S CONFIDENTIAL csv-1
Sony Service Company
National Technical Services Service Bulletin
A Division of Sony Electronics Inc.
Park Ridge, New Jersey 07656 TV Products
Model: KV-24FV10, KV-27FV15, KV-32FV1, KV-32FS10
KV-32FV15, KV-32XBR200, KV-32XBR250 No. 425
KV-36FV1, KV-36FS10, KV-36FV15
KV-36XBR200, KV-36XBR250
Date: October 7, 1999
Subject: Part Number for TLH Plate

Symptom:
(XXXX) Need the part number for the TLH plate, which slides into the Yoke.

Solution: If a yoke needs replacement, the TLH plate should be removed from the old yoke,
and inserted into the new yoke. If the TLH Plate was lost or misplaced the TLH plate
part number is listed below.

Chassis Description Part Number

AA-2H, AA2-W TLH Plate (Gray) 2-163-920-11

BA-4C (KV-24FV10) TLH Plate (White) 4-057-714-01

VIII

NOTE: The two TLH Plates are not interchangeable.

The TLH plate can be inserted into either the left or right side of the Yoke. There is only
one plate; therefore during alignment the plate must be tried in both sides of the Yoke to
determine the most effective adjustment position.

The alignment procedure for the Yoke replacement can be found in

Service Bulletin 387R2

TLH Plate
Slot (right side)
THL
slot (left side)

Reference: FPR-U0898 PRINTED IN USA

S CONFIDENTIAL csv-1
Sony Service Company
National Technical Services Service Bulletin
A Division of Sony Electronics Inc.
Park Ridge, New Jersey 07656 TV Products
Model: KV-32XBR250, KV-36XBR250
No. 432

Date: November 4, 1999

Subject: Headphone Part Number Missing

Symptom:
(XXXX) The part number for the Headphone MDR-IF0230 is not listed in the Service Manual.

Solution: Please add the following part number to the Service Manual.

REF DESCRIPTION PART NUMBER

HEADPHONE (MDR-IF0230) 8-953-742-90

IX

Reference: FPR-U1120 PRINTED IN USA

 S CONFIDENTIAL csv-1
Sony Service Company
National Technical Services Service Bulletin
A Division of Sony Electronics Inc.
Park Ridge, New Jersey 07656 TV Products
Model: KV-27FV15, KV-32FS10, KV-32FV15
KV-32XBR250, KV-36FS10, KV-36FV15 No. 438
KV-36XBR250

Date: November 15, 1999

Subject: Control Door Breakage

Symptom:
(161X) Weak or broken Control Door hinges

Solution: If the customer should complain of the above symptom, please replace the Control
Door Assembly, with the new improved part.

Model Description Part Number

KV-27FV15 Control Door Assembly X-4037-631-3

KV-32FS10 Control Door Assembly X-4037-631-2

KV-32FV15 Control Door Assembly X-4037-631-3

X

KV32XBR250 Control Door Assembly X-4037-631-3

KV-36FS10 Control Door Assembly X-4037-631-2

KV-36FV15 Control Door Assembly X-4037-631-3

KV-36XBR250 Control Door Assembly X-4037-631-3

Reference: TV99-09 PRINTED IN USA

S CONFIDENTIAL csv-1
Sony Service Company
National Technical Services Service Bulletin
A Division of Sony Electronics Inc.
Park Ridge, New Jersey 07656 TV Products
Model: KV-27FV15, KV-32FS10, KV-36FS10
KV-32FV15, KV-36FV15, KV-32XBR250 No. 441
KV-36XBR250

Date: November 22, 1999

Subject: S-Link, IR Headphone, OSD, and 3D Comb
Filter Mis-Operation

Symptom:
(172X) The following Symptoms may occur:

1. S-LinK: When the TV detects the S-Link signal in stand-by mode. TV is

supposed to automatically turn on and select appropriate video input. It does turn
on, but it does not select the appropriate input.

2. OSD: When customer tries to enter password for V-chip in Spanish menu,
customer will see additional unnecessary letters Pr preceding correct OSD.

3. IR Headphone: In XBR models only. When customer swaps audio of main

picture and PIP picture, customer can hear the audio of PIP picture even when it
is supposed to be blocked.

XI
4. 3D Comb Filter: In XBR model only, when customer changes video input from S
to composite, customer can see a Black & White picture, less than one second,
then color returns.

Solution: If the customer should complain of the following symptoms please do the following:

27 inch models:

1. In the service Mode record on paper the following register information in both RF & Video mode:
VP SHUE RF Data ______ Video Data:_______
VP SCOL RF Data_______ Video Data:________
VP SSHP RF Data_______ Video Data_________

2. 1) Replace the CPU (IC001)

2) Enter the service Mode using the remote. Then press 8 then Enter.
This will reset the CPU, turning the set off then back on automatically.
3) Re-enter the Service Mode.
4) In the RF mode replace the data in the SHUE, SCOL, & SSHP with the
recorded data from the original CPU.
5) In the Video mode replace the data in the SHUE, SCOL, & SSHP with the
recorded data from the original CPU.
6) Change the Data of ID7 from 0 to 2.
7) Write the new data into the CPU using the remote press the Mute then
Enter key.

32/36 Non XBR Models:

Reference: Uchida, K. PRINTED IN USA

 32/36 Non XBR Models:

1. In the service Mode record on paper the following register information in both RF & Video mode:
VP SSHP RF Data ______ Video Data:_______
DA 2COL RF Data ______ Video Data:_______
DA 2SHU RF Data ______ Video Data:________
2. 1) Replace the CPU (IC001)
2) Enter the service Mode using the remote. Then press “8” then “Enter.”
This will reset the CPU, turning the set off then back on automatically.
3) Re-enter the Service Mode.
4) In the RF mode replace the data in the 2SHU, 2COL, & SSHP with the
recorded data from the original CPU.
5) In the Video mode replace the data in the 2SHU, 2COL, & SSHP with the
recorded data from the original CPU.
6) Change the Data of ID7 from 0 to 2.
7) Write the new data into the CPU using the remote press the “Mute” then “Enter” key.
32/36 XBR models:

1. In the service Mode record on paper the following register information in both RF & Video mode:
VP SSHP RF Data ______ Video Data:_______
DA 2COL RF Data ______ Video Data:_______
DA 2SHU RF Data ______ Video Data:_______
2. 1) Replace the CPU (IC001)
2) Enter the service Mode using the remote. Then press “8” then “Enter.”
This will reset the CPU, turning the set off then back on automatically.
3) Re-enter the Service Mode.
4) In the RF mode replace the data in the 2SHU, 2COL, & SSHP with the
recorded data from the original CPU.
5) In the Video mode replace the data in the 2SHU, 2COL, & SSHP with the
recorded data from the original CPU.
XII

6) Change the Data of ID7 from 9 to 11.

7) Write the new data into the CPU using the remote press the “Mute” then “Enter” key.

Model Ref Former New Part Number

KV-27FV15 IC001 CXP85856A-029S CXP85856A-035S 8-752-911-19

KV-32FS10 IC001 CXP85856A-024Q CXP85856A-035S 8-752-911-19

KV-36FS10 IC001 CXP85856A-024Q CXP85856A-035S 8-752-911-19

KV-32FV15 IC001 CXP85856A-024Q CXP85856A-035S 8-752-911-19

KV-36FV15 IC001 CXP85856A-024Q CXP85856A-035S 8-752-911-19

KV- IC001 CXP85856A-024Q CXP85856A-035S 8-752-911-19

32XBR250

KV- IC001 CXP85856A-024Q CXP85856A-035S 8-752-911-19

36XBR250
EURAS Repair Tip Database
Model: SONY AE4 Fault area (1): COLOUR

Symptom (1)
Changing background colour in TXT V2.5
Fault
This is a feature of TXT V2.5. Feature can be switched off through TT18. Close off with TT00. TT17 will undo this again if
necessary.

Symptom (2)
Blue is predominant.
Fault
Legs of R711 are too long and S/C. Cut legs off to correct size.
Location Section
C-board VPA

Model: SONY AE4 Fault area (2): PICTURE

Symptom (2)
Picture runs vertically.
Fault
Deflection processor IC403 is defective through which there is no V-sync on pin 28 of IC403. Replace IC403 SDA9361 no.
(8-759-421-42).

Symptom (4)
No picture.
Fault
Short between pin 66 and 67 (on A-board) of IC201.

Symptom (5)
Picture is very dark and only consists of chroma info.
Fault
Poor contact of connector CN1810, connection between A board and B board. Disconnect white wire and restore contacts.

Symptom (1)
Jitters Vertically in PAL plus mode.
Fault
Data corruption or incorrect setting. Via service (TT) mode using the menu keys on the remote control go to "features box"
in the devices overview. Set the value of register 78 ('R22 HWE 1 main) in at 65.

Symptom (3)
No sync, only lines.
Fault
Crystal X1801 is defective. Replace X1801 (10MHz) 1-579-175-11 on the B-board VPD (between pin 20 and 21 of IC1816).

Model: SONY AE4 Fault area (3): AUDIO

Page: 1 Date: 17.3.2003 CD-ROM: 10.2002 Hardlock: 2000-07-11-15-40-50 Copyright by EURAS International Ltd.
EURAS Repair Tip Database
Symptom (1)
Noisy hissing sound and static from the speakers.
Fault
Sound processor IC201 (MSP3400CPS-C6-T) is defective, replace IC201 (8-759-376-56). The IC is extremely temperature
sensitive.

Symptom (2)
Hum from centre and surround speakers.
Fault
Interference of vertical deflection. To reduce hum reposition signal and supply leads between K board and D board.
Distance between leads and CN0745 must be as big as possible.

Model: SONY AE4 Fault area (4): POWER

Symptom (1)
Dead.
Fault
Transformer T602 on the G-board has S/C. P/N: 1-427-864-11

Symptom (2)
Dead or switches off immediately. No error code given.
Fault
IC802 (Vertical out) on D-board is defective. R818 and/or R819 possible also open circuit. Replace IC802. Add a diode
between pin 2 (IC802) and earth. Do the same between pin 4 and earth. cover the entire top side of the heatsink with
insulating tape.
IC802 STV9379 8-759-192-71
D875 MTZL20D 8-719-048-52
D876 MTZL20D 8-719-048-52
R818 0.47ohm 1-249-377-11 (fusible)
R819 0.47ohm 1-249-377-11 (fusible)

Model: SONY AE4 Fault area (5): FUNCTION

Symptom (1)
Dead.
Fault
B board supplies incorrect pulses, causing defective Q802. Replace B board and Q802.

Ref. Description Location Part no.

Q802 2SC3997CA D-Board DFL 8-729-821-07
B-Board B-Board compl. B-Board DFL A-1620-077-A

Symptom (2)
No function.
Fault
. Clock error of the I2C bus signals (SDL and SCL) as a result of a malfunction of the tuner BTP-EC411 (8-598-045-00 or
8-598-045-01). In the tuner change the grounding connection at TSA5512T (PLL).

Model: SONY AE4 Fault area (6): GEOMETRY

Page: 2 Date: 17.3.2003 CD-ROM: 10.2002 Hardlock: 2000-07-11-15-40-50 Copyright by EURAS International Ltd.
EURAS Repair Tip Database
Symptom (1)
Picture is too small with pincushion distortion.
Fault
PIN drive Q803 is defective. Replace transistor (FET) Q803 on D-board, no. 8-729-039-68.

Page: 3 Date: 17.3.2003 CD-ROM: 10.2002 Hardlock: 2000-07-11-15-40-50 Copyright by EURAS International Ltd.
USEFUL INFO.
Error reader.
The BE-3D chassis supports the use of the Error Reader. This jig, is available under part number S-188-900-10
(price code S).

The displayed code shows the actual error of the TV set. Refer to the service manual or the table below for an
explanation of those codes.

ERROR CODES
02 - Protection circuit trip <ANY TIME>
03 - IIC SCL LOW <POWER UP ONLY>
04 - IIC SDA LOW <POWER UP ONLY>
05 - IIC SDA and SCL LOW <POWER UP ONLY>
06 - Jungle/chroma controller no acknowledge <POWER UP ONLY>
07 - Video switch no acknowledge <POWER UP ONLY>
08 - Tuner no acknowledge
09 - MSP no acknowledge
10 - NVM no acknowledge
11 - M3L TXD LOW <POWER UP ONLY>
12 - M3L RXD LOW <POWER UP ONLY>
13 - M3L ENABLE LOW <POWER UP ONLY>
14 - M3L TXD AND RXD LOW <POWER UP ONLY>
15 - Compact Text test fail <POWER UP ONLY>
16 - AV switch cannot power on reset
17 - Cannot initialise jungle
18 - NVM acknowledge fail after initialisation
19 - Multiple devices with no acknowledge <POWER UP ONLY>
20 - Compact Text run-time failure
21 - AVSWITCH response failure after power up
22 - JUNGLE/CHROMA controller response failure after power up
23 - Compact Text does not respond
24 - Sound processor run time failure
25 - M3L bus clock low time-out after data sent (run time failure)
26 - M3L bus clock low time-out afetr data sent (power up)
27 - M3L bus clock low time-out afetr data sent (initialization)
28 - DSP run-time failure.

Replacement of HV transformer.
Two types of high voltage transformer are used (removable or fixed focus cable). When replacing a line
transformer, replace using the original type.
Type Focus cable Part no.
A Removable 1-453-169-12
B Fixed 1-453-220-11

DEFLECT
Lines tearing when hot.
[32in models only]. Replace line driver transformer T804.

No sync in TXT mode.

Replace IC1001.

PICTURE

 

Horizontal interference in picture during first half hour.
IC606 is defective. Therefor unstable +9V (pin 3 of IC606). Replace 9V regulator IC606.
Ref. Description Location Part no.
IC606 LM2940T-90 D-board PSU 8-759-267-25

Visible arcing interference on screen when appliance does function. Intermittently switches off when switched
on.
Replace line output transformer T803.

Partially blanked horizontally.

Check zener diode D817 (RD5.6ESB2) in blanking circuit, for leaks.

Overbright, nearly negative picture.

Access service mode and enter TT07 to clear.

AUDIO
Hum and/or buzz of the headphones and/or speaker when vol. is low.
Deflection unit generates interference. On board A, solder side, add a thick wire AWG18 200mm long between
pins 6,7 and 8 of IC203 and pins 29 and 30 of CN1. Given its critical position, the wire must be kept away from
board A.
Part no. Ref.
190090227 Wire AWG18

No sound. Headphones OK.

Fau;t 1: [PS6001 O/C]. Replace audio output chip IC1200 (TDA7264).

Distorted or loud crackling from audio.

Check audio demodulator/processor chip IC202 (MSP3410).

POWER
POWER
EHT comes up briefly then nothing. No error code.
[Excess current protection system operating]. Check line output transformer T803.

Intermittently switches off when switched on. Visible arcing interference on screen when appliance does
function.
Replace line output transformer T803.

Locks when hot.

Replace IC202 (MSP3410).

Shuts down when hot.

Replace IC202 (MSP3410).

FUNCTION
No TXT. No OSD.
Check zener diode D817 (5.1V) on main PCB.

Comes on then switches to standby. Standby LED flashes twice.

(1) Check field output chip IC500 (STV9379).
(2) [OK if D505 disconnected]. Check zener diode D505 (MTZJT7736A) for leaks.
(3) [No change if D505 disconnected]. Replace memory chip NVM IC2.

 

 Does not got into standby mode completely; picture disappears but line continues to run.
(1) Check Q602, Q603 and Q604 in standby switching circuit. Check reservoir capacitor C615.
(2) [Above components replaced; HT not at 135V]. Replace error detector chip IC602 (SE135N).

Pulses in and out of standby. RY600 clicks each time.

Check Q601 (2SC3852A), D603 (6.8V) zener and R634 (22R) on primary side of PSU.

Degaussing incomplete.
Replace relay RY600 with part number 1-755-018-11.

TUNING/MEMORY
Intermittently channels change.
Replace tactile switches S9001 and S9002 on D board.

GEOMETRY
E-W bowing. Excessive width.
Check R870 (1R/1W).

OTHER
No OSD. No TXT.
Check zener diode D817 (5.1V) on main PCB.

Intermittently volume bar appears.

Replace tactile switches S9001 and S9002 on D board.

Incomplete or messy OSD and menus. TXT OK.

Replace IC1001.