COMPUTER

MAINTENANCE AND
TECHNICAL SUPPORT

BY: Dessalew G.
 CHAPTER ONE
Basics of Computer Maintenance and
Technical Support
2
 List of Contents

◉ General concepts about PC and tech support

◉ Lab procedures and maintenance tools
◉ Static energy and its effect on computers
◉ Safety rules
◉ Preventive maintenance and troubleshooting

3
 1. General concepts about PC and tech support

◉ Computer systems include hardware, software, and

firmware.
○ Hardware is something you can touch and feel.
■ The physical computer and the parts inside the
computer are examples of hardware.
○ Software interacts with the hardware.
■ Windows, Linux, OS X, Microsoft Office,
Solitaire, Google Chrome, Adobe Acrobat
Reader, and WordPerfect are examples of
software. 4
 Continued…

◉ Without software that allows the hardware to

accomplish something, a computer is nothing more
than a doorstop.
◉ Every computer needs an important piece of
software called an operating system, which
coordinates the interaction between hardware and
software applications.
◉ The operating system also handles the interaction
between a user and the computer.
5
 Continued…

○ Examples of operating systems include DOS,

Windows XP, Windows Vista, Windows 7, OS X,
and various types of Unix, such as Red Hat and
Mandrake.

◉ A device driver is a special piece of software

designed to enable a hardware component.
○ The device driver enables the operating system to
recognize, control, and use the hardware
component. 6
 Continued…

◉ Device drivers are, hardware and operating system

specific.
○ For example, a printer requires a specific device
driver when connected to a computer loaded with
Windows 98.
○ The same printer requires a different device driver
when using Windows XP.

7
 Continued…

◉ Software applications are normally loaded onto the

hard drive.
◉ When a user selects an application, the operating
system controls the loading of the application.

◉ The operating system also controls any hardware

devices such as:
○ mouse, keyboard, monitor, printer, that must be
accessed by the application.
8
 Continued…

◉ Figure 1.1
shows how
hardware and
software must
work together.

Figure 1.1 Hardware and software 9

 Continued…

◉ Firmware combines hardware and software into

important chips inside the computer.
◉ It is called firmware because it is a chip, which is
hardware, and it has software built into the chip.
○ An example of firmware is the BIOS (basic
input/output system) chip.
○ BIOS chips always have software inside them.
○ The BIOS has startup software that must be present
for a computer to operate.
10
 ?

◉ Where to start to learn about computer

repair?

11
 1.1 Hardware Components

◉ The simplest place to start to learn about computer

repair is with the hardware components and their
common names.
◉ A computer, sometimes called a microcomputer or a PC,
is a unit that performs tasks using software applications.
◉ Computers come in three basic models:
○ desktop model that normally sits on top of a desk;
○ tower model that sits under a desk; and
○ laptop model, which is portable.
12
 Continued…

◉ A computer consists of
○ a case (chassis),
○ a keyboard that allows users to provide input into the
computer,
○ a monitor that displays information,
○ a mouse that allows data input or is used to select
menus and options.
◉ Once the case is removed from the computer, the parts
inside can be identified.
13
 Continued…

◉ The easiest part to identify is the power supply, which is

the metal box normally located in a back corner of the case.
◉ A power cord goes from the power supply to a wall outlet
or surge strip.
◉ One purpose of the power supply is to convert the AC
voltage that comes out of the outlet to DC voltage the
computer can use.
◉ The power supply also supplies DC voltage to the internal
parts of the computer.
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 Continued…

◉ A fan located inside the power supply keeps the

computer cool, which avoids damage to the
components.
◉ A computer usually has a device to store software
applications and files.
◉ Two examples of storage devices are the floppy drive
and the hard drive.

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 Continued…

◉ The floppy drive allows data storage to floppy disks

(sometimes called diskettes or disks) that can be used
in other computers.
◉ Floppy disks store less information than hard drives.
◉ The hard drive, sometimes called hard disk, is a
rectangular box normally inside the computer’s case
that is sealed to keep out dust and dirt.
◉ In a desktop computer, the hard drive is normally
mounted below or beside the floppy drive.
16
 Continued…

◉ A CD drive holds disks (CDs) that have data, music, or

software applications on them.
◉ A popular alternative to a CD drive is a DVD drive
(digital versatile disk drive), which supports CDs as well
as music and video DVDs.
◉ The motherboard is the main circuit board located
inside a PC and contains the most electronics.
◉ Other names for the motherboard include mainboard,
planar, or system board.
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 Continued…

◉ The motherboard is the largest electronic circuit board

in the computer.
◉ Some devices have a cable that connects the device
to the motherboard.
◉ Other devices require an adapter.
○ Adapters are electronic circuit cards that normally plug
into an expansion slot on the motherboard.
○ Other names for an adapter are controller, card,
controller card, circuit card, circuit board, and adapter
board. 18
 Continued…

Figure 1.2 Tower computer components

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 Continued…

◉ Memory is an important part of any computer.

◉ Memory chips hold applications, part of the operating
system, and user documents.

◉ Two basic types of memory are RAM and ROM.

○ RAM (random access memory) is volatile memory meaning
the data inside the chips is lost when power to the computer
is shut off.
○ ROM (read-only memory) is nonvolatile memory because data
stays inside the chip even when the computer is turned off.
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 Continued…

Figure 1.3 Motherboard with expansion slots, adapter and memory

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 Continued…

◉ Part of the startup software the motherboard BIOS

contains is POST (power on self test).
◉ POST performs a basic test of the individual hardware
components such as the motherboard, RAM memory
chips, keyboard, floppy drive, and hard drive.
◉ When a computer is turned on with the power switch,
BIOS executes POST.
○ Numbers appearing in the upper-left corner of the
monitor indicate that POST is checking RAM.
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 1.1.1 External Connectivity

◉ A port is a connector on the motherboard or on a

separate adapter that allows a device to connect to the
computer.

◉ Sometimes a motherboard has ports built directly into

the motherboard.

◉ Motherboards that have ports built into them are called

integrated motherboards.
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 Continued…

○ A technician must be able to identify these

common ports readily to ensure that
1. the correct cable plugs into the port; and
2. the technician can troubleshoot problems in the
right area.
◉ Many port connections are referred to as male or
female.
○ Male ports have metal pins that protrude from the connector.
○ Female ports have holes in the connector into which the male
cable pins are inserted.
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 Continued…

◉ Many connectors on integrated motherboards are

either D-shell connectors or DIN connectors.
◉ A D-shell connector has more pins or holes on top
than on the bottom, so a cable connected to the D-
shell connector can only be inserted in one direction
and not accidentally flipped upside down.
○ Parallel, serial, and video ports are examples of D-shell
connectors.
○ Many documents represent a D-shell connector by using the
letters DB, a hyphen, and the number of pins as DB-9, DB-15….
25
 Continued…

◉ A DIN connector is round with small holes and is

normally keyed.
◉ When a connector is keyed it has an extra metal piece
or notch that matches with an extra metal piece or
notch on the cable, and the cable can only be inserted
into the DIN connector one way.
○ Older keyboard and mouse connectors are
examples of DIN connectors

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 Continued…

Figure 1.4 DIN and D-Shell connectors

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 1.1.2 Video Port

◉ A video port is used to connect a monitor.

◉ Today, there are two types normally seen and they both have
three rows.
◉ The older one is a three-row, 15-pin female D-shell.
○ The 15-pin female connector is used to attach VGA, SVGA,
XGA, SXGA, or UXGA monitors
○ Even though it can have different types of monitors attached,
it is normally referred to as a VGA (Video Graphics Array) port.
◉ The newer port is called a DVI port (Digital Visual Interface) and it
has three rows of square holes.
◉ This is used to connect flat panel
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digital monitors.
 Continued…

◉ Flat panel monitors can also

use the older VGA port.
◉ There are actually different
types of DVI ports.

◉ Some video adapters also

allow you to connect a video
device (such as a television)
that has an S-Video port.
Figure 1.5 Video ports
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 1.1.3 USB port

◉ USB stands for Universal Serial Bus.

◉ A USB port allows up to 127 devices to transmit at speeds up to
5Gbps (5 billion bits per second) with version 3.0.
◉ Devices that can connect to the USB port include
○ printers, scanners, mice, keyboards, joysticks, CD drives, DVD
drives, tape drives, floppy drives, cameras, modems,
speakers, telephones, video phones, data gloves, and
digitizers.
◉ In order for the computer to use the USB port, it must have a
Pentium or higher CPU; and operating system that supports USB
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 Continued…

◉ USB ports and devices come in three versions:

○ Version 1.0 supported speeds of 1.5Mbps and 12Mbps.
○ Version 2.0 increased the supported speed to 480Mbps; and
○ Version 3.0 supports speeds up to 5Gbps.

Figure 1.6 USB ports

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 Continued…

◉ Converters are available to convert a USB port to a different type

of connector (or vice versa), such as serial, parallel, or mini-DIN.
◉ A smaller USB port used on small devices such as a USB hub,
PDA, digital camera, and phones is known as a mini-USB port.
◉ There are three types of mini-USB ports: mini-A, mini-B, and mini-
AB.

Figure 1.7 Mini-DIN to USB converter Figure 1.8 Mini-B and a standard A USB
32 connectors (as well as IEEE 1394 connectors)
 1.1.4 Parallel and serial ports

◉ The parallel port is a 25-pin female D-shell connector used to

connect a printer to the computer.
○ Some motherboards have a small picture of a printer
imprinted over the connector.

◉ A serial port (also known as a COM port or an asynchronous

(async) port) can be a 9-pin male D-shell connector or a 25-pin
male D-shell connector (on very old computers).
○ Serial ports are used for a variety of devices including mice,
external modems, digitizers, printers, PDAs, and digital
cameras.
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 1.1.5 IEEE 1394 Port

◉ The IEEE 1394 standard is a serial technology developed by Apple

Computer.
◉ Sometimes it is known as FireWire or i.Link, which is a Sony
trademark.
◉ IEEE 1394 ports have been more predominant on Apple
computers, but are now becoming a standard port on PCs.
◉ Windows and Apple operating systems support the IEEE 1394
standard.
◉ Speeds supported are 100, 200, 400, 800, and 1200Mbps.
◉ As many as 63 devices (using cable lengths up to 14 feet) can be
connected with FireWire. 34
 Continued…

◉ The IEEE 1394 standard supports hot swapping (plugging and

unplugging devices with the power on), plug and play, and
powering low-power devices.

Figure 1.9 IEEE 1394 adapter ports Figure 1.10 IEEE 1394 laptop port
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 1.1.6 Network ports

◉ Network ports are used to connect a computer to other

computers, including a network server.
◉ Two different network adapters, Ethernet and Token Ring, are
available, but most networks use Ethernet ports.
◉ The ports on these adapters can be quite confusing because the
connectors are sometimes the same.
○ Ethernet adapters are the most common type of NIC (network
interface card/controller).
○ They can have a BNC, an RJ-45, a 15-pin female D-shell
connector, or a combination of these on the same adapter.

36
 Continued…

◉ Token Ring adapters are not as popular as Ethernet, and they can
have two different connectors: RJ-45 and/or 9-pin female D-shell
connectors.
◉ Some adapters have a little green sticker with the numbers 4/16
on it, which indicates the two speeds, 4Mbps and 16Mbps, at
which Token Ring adapters can run.
◉ The 4/16 sticker is a helpful indicator that the port is a Token Ring
port.

37
 Continued…

Figure 1.11 Ethernet ports Figure 1.12 Token Ring ports

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 1.1.6 Modem Ports

◉ A modem connects a computer to a phone line.

◉ A modem can be internal or external.
◉ An internal modem is an adapter that has one or two RJ-11
connectors.
◉ An external modem is a separate device that sits outside the
computer and connects to a 9-pin or 25-pin serial port.
◉ The external modem can also have one or two RJ-11 connectors.
The RJ-11 connectors look like typical phone jacks.
○ The RJ-11 connector labeled Line is for the connection to the wall jack.
○ The RJ-11 connector labeled Phone is for the connection to the phone.

39
 Continued…

Figure 1.13 Internal modem with two ports

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 1.1.7 Docking Station and Port Replicator

◉ Docking stations and port replicators add connectivity

and expansion capability to laptop computers.
◉ A docking station allows a laptop computer to be more
like a desktop system.
◉ A docking station can have connections for a full-size
monitor, printer, keyboard, mouse, and printer.
◉ In addition, a docking station can have expansion slots
or cards and storage bays.

41
 Continued…

◉ The port replicator is similar to a docking station, but

does not normally include an expansion slot or drive
storage bays.
◉ The port replicator attaches to the laptop and allows
more devices to be connected, such as an external
monitor, keyboard, mouse, joystick, and printer.
◉ To use a port replicator, normally the external devices
are connected first.

42
 Continued…

Figure 1.30 a laptop installed in a docking station

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 1.2 Technical Support

◉ A computer technician must be a jack-of-all-trades:

○ a software expert in various operating systems and
applications;
○ a hardware expert in everything ranging from
processors to the latest laser printer;
○ a communicator extraordinaire to handle the
occasional irate, irrational, or computer illiterate
customer;
○ a good listener to elicit computer symptoms from
customers (and from the computer);
44
 Continued…

○ an empathetic counselor to make customers feel

good about their computers and confident in the
technician’s skills; and
○ finally, a master juggler of time and priorities.

◉ These skills do not come overnight and not all of them

can be taught
○ but a technician can constantly develop and fine-
tune each of them.
45
 Continued…

◉ There is no substitute for experience !!!

46
 Continued…

◉ Once a technician has a job in the industry, past hands-

on time will increase his or her depth of knowledge and
experience.
◉ The classroom is the place to learn the ropes (the
basics).
◉ A good technician narrows a problem to a general area,
subdivides the problem into possible culprits, and
eliminates the possibilities one-by-one efficiently and
logically.
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 Continued…

◉ The best quality a technician can possess is logic.

◉ A technician is like a detective, constantly looking for
clues, using common sense and deductive reasoning,
gathering information from the computer and the
computer user, and finally solving the mystery.
◉ Repairing computers is rewarding, but it can be
frustrating if you do not understand the basics.
◉ With good reasoning ability and a good foundation in
computer repair, no problem goes unsolved.
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 2. Lab Procedures and Maintenance Tools

◉ Safety guidelines help protect individuals from

accidents and injury.

◉ They also help to protect equipment from damage.

◉ Some of these guidelines are designed to protect the

environment from contamination caused by improperly
discarded materials.

49
 2.1 Lab procedures

◉ Basic lab procedures for technicians

○ Work in a safe manner to protect users and
equipment.
○ Follow all safety guidelines to prevent injuries to
yourself and others.
○ Know how to protect equipment from ESD damage.
○ Know about and be able to prevent power issues
that can cause equipment damage or data loss.
○ Know which products and supplies require special
disposal procedures.
50
 Continued…

○ Familiarize yourself with the MSDS (Material safety

data sheet) for safety issues and disposal restrictions
to help protect the environment.

○ Be able to use the correct tools for the task.

○ Know how to clean components safely.

○ Use organizational tools during computer repairs.

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 2.2 Maintenance Tools

◉ For every job there is the right tool.

◉ Make sure that you are familiar with the correct use of
each tool and that the correct tool is used for the
current task.
◉ Skilled use of tools and software makes the job less
difficult and ensures that tasks are performed properly
and safely.
◉ A toolkit should contain all the tools necessary to
complete hardware repairs.
52
 Continued…

◉ Hardware tools are grouped into four categories:

○ ESD tools
○ Hand tools
○ Cleaning tools
○ Diagnostic tools

53
 Continued…

◉ ESD tools:
○ There are two ESD tools: the antistatic wrist strap
and the antistatic mat.
■ The antistatic wrist strap protects computer
equipment when grounded to a computer
chassis.
■ The antistatic mat protects computer equipment
by preventing static electricity from accumulating
on the hardware or on the technician.
54
 Continued…

◉ Hand tools:
○ Most tools used in the computer assembly process
are small hand tools.

○ They are available individually or as part of a

computer repair toolkit.

○ Toolkits range widely in size, quality, and price.

55
 Continued…

Some of the hand tools technician must have are:

• Different screwdrivers
• Tweezers or part retriever
• Needle-nosed pliers
• Wire cutters
• Chip extractor
• Hex wrench set
• Soft, lint-free cloth
• Cable ties
• Electrical tape
56
 Continued…

• Three-claw component holder

• Wire Stripper
• Crimper
• Punch Down Tool
• Wrap plugs
• Small mirror
• Small dust brush
• Scissors
• Small flashlight
• Pencil or pen
57
 Continued…

◉ Various specialty tools, such as Torx bits, antistatic

bags and gloves, and integrated circuit pullers, can
be used to repair and maintain computers.
◉ Always avoid magnetized tools, such as
screwdrivers with magnetic heads, or tools that use
extension magnets to retrieve small metal objects
that are out of reach.
◉ Using magnetic tools can cause loss of data on hard
drives and floppy disks. 58
 Continued…

◉ Cleaning tools:
○ Having the appropriate cleaning tools is essential
when maintaining and repairing computers.

○ Using the appropriate cleaning tools helps ensure

that computer components are not damaged during
cleaning.

59
 Continued…

○ Keeping computers clean inside and out is a vital

part of a maintenance program.
○ Dirt can cause problems with the physical operation
of fans, buttons, and other mechanical components.

◉ Note: When using compressed air to clean inside the

computer, blow the air around the components with a
minimum distance of 4 inches (10 cm) from the nozzle.
Clean the power supply and the fan from the back of the
case.
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 Continued…

○ Caution: Before cleaning any device, turn it off and

unplug the device from the power source.

61
 Continued…

◉ Diagnostic tools:
○ Digital Multimeter
■ It is a device that can take many types of
measurements.
■ It tests the integrity of circuits and the quality of
electricity in computer components.
○ Loopback Adapter
■ tests the basic functionality of computer ports.
■ The adapter is specific to the port that you want
to test.
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 Continued…

○ Toner Probe
■ It is a two-part tool.
■ The toner part is connected to a cable at one end
using specific adapters, such as an RJ-45, coaxial,
or metal clips.
■ The probe part traces the cable.
■ When the probe is in near proximity to the cable
to which the toner is attached, the tone can be
heard through a speaker in the probe.

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 Continued…

○ External Hard Drive Enclosure

■ The customer hard drive is placed into the
external enclosure for inspection, diagnosis, and
repair using a known-working computer.

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 Continued…

◉ Organizational tools:
○ A technician must document all repairs and
computer problems.
○ The documentation can then be used as a reference
for future problems or for other technicians who may
not have encountered the problem before.
○ The documents can be paper-based, but electronic
forms are preferred because they can be easily
searched for specific problems.
65
 Continued…

○ Organizational tools includes:

■ Personal Reference Tools
● troubleshooting guides, manufacturer
manuals, quick reference guides, and repair
journals.
■ Internet Reference Tools
● Internet search engines, News groups,
Manufacturer FAQs, Online computer
manuals, Online forums and chat, Technical
websites.
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 Continued…

◉ Software tools:
○ Software tools help diagnose computer and network
problems and determine which computer device is
not functioning correctly.

○ A technician must be able to use a range of software

tools to diagnose problems, maintain hardware, and
protect the data stored on a computer.

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 Continued…

○ Basic software maintenance tools:

■ FDISK - Creates and deletes partitions on a hard
drive. The FDISK tool is not available in Windows
XP, Vista, or 7. It has been replaced with the Disk
Management tool.
■ Disk Management - Initializes disks, creates
partitions, and formats partitions.
■ Format - Prepares a hard drive to store
information.

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 Continued…

■ Scandisk or CHKDSK - Checks the integrity of

files and folders on a hard drive by scanning the
file system. These tools might also check the disk
surface for physical errors.
■ Defrag - Optimizes space on a hard drive to allow
faster access to programs and data.
■ Disk Cleanup - Clears space on a hard drive by
searching for files that can be safely deleted.

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 Continued…

■ System File Checker (SFC) - Scans the operating

system critical files and replaces files that are
corrupted. Use the Windows 7 boot disk for
troubleshooting and repairing corrupted files. The
Windows 7 boot disk repairs Windows system
files, restores damaged or lost files, and reinstalls
the operating system.
● Third-party software tools are also available to
assist in troubleshooting problems.

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 Continued…

■ Windows 7 Action Center - Checks the status of

essential security settings.
■ Antivirus program - Protects against virus attacks.
■ Window 7 Firewall - Runs continuously to protect
against unauthorized communications to and
from your computer.
■ Antispyware program - Protects against software
that sends information about web surfing habits
to an attacker

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 3. Static energy and its effect on computers

◉ Static electricity can damage electronic equipment

without the technician’s knowledge.
◉ The average person requires a static discharge of 3,000
volts before he or she feels it.
◉ An electronic component can be damaged with as little
as 30 volts.
◉ Some electronic components may not be damaged the
first time static electricity occurs.

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 Continued…

◉ However, the effects of static electricity can be

cumulative, weakening or eventually destroying a
component.
◉ An ESD event is not recoverable, nothing can be done
about the damage it induces.
◉ Electronic chips and memory modules are most
susceptible to ESD strikes.
◉ Atmospheric conditions affect static electricity.

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 Continued…

◉ When humidity is low, the potential for ESD is greater than

at any other time.
◉ Keep humidity above 50 percent to reduce the threat of
ESD.
◉ A technician can prevent ESD by using a variety of
methods.
◉ The most common tactic is to use an antistatic wrist strap.
○ One end encircles the technician’s wrist.
○ At the other end, an alligator clip attaches to the
computer.
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 Continued…

◉ If an antistatic wrist strap is not available, you can still

reduce the chance of ESD damage.
◉ After removing the computer case, if you are right-handed,
place your bare left arm on the power supply.
◉ Remove the computer parts one by one, always keeping
your left elbow (or some bare part of your arm) connected
to the power supply.
◉ If you are left-handed, place your right arm on the power
supply.
◉ It is not as safe as using an75antistatic wrist strap.
 Continued…

◉ Also, removing the power cable from the back of the

computer is a good idea.
◉ Power supplies provide a small amount of power to the
motherboard even when the computer is powered off.

◉ Note: Technicians should not wear an ESD wrist strap

when working inside a CRT monitor because of the high
voltages there.
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 4. Safety Rules

◉ To protect yourself and the computer, make sure the

computer power is off when disassembling, installing,
or removing hardware, or doing preventive maintenance
(cleaning).

◉ Never take the monitor or power supply apart unless

you have been specifically trained on these
components.

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 Continued…

◉ The power supply and monitor have capacitors

(electronic parts that hold an electrical charge), which
can hurt you even if the power has been removed.

◉ Follow the basic laboratory procedures properly.

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 5. Preventive maintenance and
troubleshooting

◉ Preventive maintenance includes certain procedures

performed to extend the life of the computer.
◉ Typical preventive measures include vacuuming the
computer and cleaning the floppy drive heads, CD/DVD
laser, keyboard keys, printers, and monitor screen.
◉ Repair companies frequently provide a preventive
maintenance kit for service calls.

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 Continued…

◉ The kit normally includes:

○ portable vacuum cleaner,
○ special vacuum cleaner bags for laser printers,
○ a can of compressed air,
○ urethane swabs,
○ monitor wipes,
○ lint-free cloths,
○ general purpose cloths,
○ general purpose cleanser,
○ denatured alcohol,
○ mouse ball cleaning kit,
○ an antistatic brush 80
 Continued…

◉ When performing preventive maintenance, power on the computer

to be certain it operates.
◉ Perform an audio and visual inspection of the computer as it boots.
◉ It is a terrible feeling to perform preventive maintenance on a
computer, only to power it on and find it does not work.
◉ You will wonder if the cleaning you performed caused the problem
or if the computer had a problem before the preventive
maintenance.
◉ Once the computer powers up, go into Setup and copy the current
settings in case the battery dies.
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 Continued…

◉ Keep this documentation with the computer.

◉ Power off the computer, remove the power cord, and vacuum it
with a non-metallic attachment.
◉ Do not start with compressed air or by blowing dust out of the
computer because the dirt and dust will simply go into the air and
eventually fall back into the computer and surrounding equipment.
◉ If you remove an adapter from an expansion slot, replace it into the
same slot.

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 Continued…

◉ The preventive maintenance call is the perfect opportunity to check

computers for viruses.
◉ Normally, first you would clean the computer.
◉ Then, while the virus checker is running, you might clean external
peripherals, such as printers.
◉ Preventive maintenance measures help limit computer problems as
well as provide a chance to interact with customers and help with a
difficulty that may seem minuscule, but could worsen.

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 Continued…

◉ NOTE: Be careful when cleaning LCD monitors and laptop displays

○ Use one of the following methods:
1. wipes specifically designed for LCDs;
2. a soft lint-free cloth dampened with either water or a
mixture of isopropyl alcohol and water.

● Never put liquid directly on the display and ensure the

display is dry before closing the laptop.
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THE END OF CHAPTER ONE

85
 CHAPTER TWO
Computer Cases and the Motherboard

86
 List of Contents

◉ Computer cases
◉ System board defined
◉ System board evolution
◉ Removing and replacing motherboard
◉ Troubleshooting the motherboard

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 1. Computer cases

◉ A computer case, also known as a computer chassis,

is the enclosure that contains most of the components
of a personal computer.
○ usually excluding the display, keyboard, and mouse.
◉ Cases are usually constructed from steel, aluminum,
plastic.
○ Other materials such as glass, wood, and even Lego
bricks have appeared in home-built cases.

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 Continued…

◉ Computer cases protect the internal components of a

PC from the outside environment and come in two
varieties
○ Desktop
○ Tower
◉ Desktop computer cases lie on a desk with the monitor
sitting on top.
◉ Towers stand upright. However, the term desktop is
now used to describe any system that is not a laptop.
89
 Continued…

◉ Towers are the most popular and there are three types:
○ mini, mid, and full.
○ The front of the case is called the bezel.
◉ Cases can come in many different sizes (known
as form factors).
◉ The size and shape of a computer case are usually
determined by the form factor of the motherboard
since it is the largest component of most computers.

90
 Continued…

◉ The form factor of a case should be the same as the

motherboard.
◉ Most desktop either support a micro ATX or ITX board.
◉ The mid tower and full tower support micro as well as
regular ATX.

91
Continued…

Figure2.1 different form factors of cases

92
Continued…

Figure 2.1 Internal structure of the Case

93
 1.1 Factors to Consider when Choosing Cases

◉ Space
◉ Number of Drive Bays
◉ Number of ports and slots
◉ Number of fans and vents
◉ Case Material
◉ Power

94
 Continued…

◉ Space:
○ If you don’t have enough space in your office or
home you may want a mini tower case. This is
because mini computer cases take up very little
space and can be tucked away nicely.
○ However, at some point you may want to fix or add
components to your PC. If so, then a mid or full
tower case is better because they provide more
space inside for additional components.
95
 Continued…

◉ Number of Drive Bay:

○ Drive bays is a space in the case where you insert
hard drives and CD/DVD drives.
○ Full tower cases usually contain far more bays than
mid or mini cases. Make sure you purchase a case
with enough bays for present and future needs.

96
Continued…

Figure 2.3 Drive bays

97
 Continued…

◉ Number of Ports & Expansion Slots:

○ Cases come equipped with a number of front panel
audio, USB, and FireWire ports as well as slots in the
back for expansion cards.
○ Get the one that's suitable for your needs.
◉ Number of Fans & Vents:
○ Make sure the case has sufficient air flow.
○ The more fans the better and many cases have
additional vents on the side.
98
 Continued…

◉ Case Material:
○ Most cases were made of aluminium, steel with
metal screws as fasteners. However modern day
cases are made of plastic and clippers as fasteners.

◉ Power Supply:
○ Many cases come with a power supply already
installed.

99
 3. System board defined

◉ A computer's motherboard (also known as

the mainboard, mobo (abbreviation), MB (abbreviation),
system board, baseboard, and even logic board) .
○ is the main printed circuit board (PCB) in general
purpose computers and other expandable systems.

○ Everything behind the computer case is connected

in some way to the motherboard so that all the
pieces can communicate with each other.
100
 Continued…

○ On the motherboard are also expansion

slots, jumpers, capacitors, device power and data
connections, fans, heat sinks, and screw holes.

101
Continued…

102 Figure 2.4 The motherboard

Continued…

Figure 2.5 The motherboard form factors

103
 Continued…

◉ To become familiar with motherboards, you need to

know and understand their parts.
◉ PC motherboard components differ depending on the
manufacturer and model.
◉ However, all have some similar primary features.

104
 3. 1 Primary Features of Motherboard

◉ BIOS
◉ CMOS
◉ Form Factor
◉ Type of Processor They Support
◉ Chipset
◉ Type of Bus & Bus Speed
◉ Expansion Slots
◉ Memory Slots
105
 BIOS

◉ The BIOS is a small program contained in a chip

located on the motherboard.
◉ It is responsible for booting up your system by reading
the CMOS settings, performs the POST (Power On Self
Test), checks for devices, and then read the Master
Boot Record (MBR) on the hard drive so the operating
system can load.
◉ Phoenix Technologies and American Megatrends are
the two main BIOS makers.
106
Continued…

107
Figure 2.5 BIOS
 CMOS

◉ Complementary Metal-Oxide Semiconductor (CMOS),

typically refers to a battery-powered memory chip in
your computer that stores startup information.
◉ The battery is used to maintain the time and CMOS
settings after the power is turned off. Most are small,
round, flat and fit into a socket.
◉ The BIOS uses the startup information in the CMOS
when starting your computer.

108
Continued…

109 Figure 2.6 CMOS

 Type Of Processor they Support

◉ Every motherboard supports either an AMD or an Intel

processor (CPU). They are therefore not
interchangeable.
◉ If a motherboard requires an AMD processor, it cannot
use an Intel processor, and vice-versa. You don't have
to figure out which CPU matches a particular board.
◉ You're always told the type of CPU that a motherboard
uses.

110
 Chipset

◉ A chip is a small piece of semiconducting material

(usually silicon).
◉ A chipset is a pair of chip on the motherboard that
allows communication between the CPU and other
components. One is called the Northbridge and the
other Southbridge.
○ The Northbridge connects the CPU directly with the memory
and video cards through the Front Side Bus.
○ The Southbridge connects slower devices such as the hard
drive, audio cards, Network indirectly to the CPU via the
Northbridge. 111
 Continued…

◉ The motherboard is useless without a chipset. Unlike

the CPU, it is integrated into the motherboard, so it can't
be removed. When a new processor is developed, a
new chipset has to also be developed to accommodate
its technology. The two main manufacturers are Nvidia
and Intel.
◉ However the chipset sets have been replaced by
HyperTranport developed by AMD and QuickPath
Interconnect developed by Intel.
112
Continued…

113 Figure2.7 Northbridge and Southbridge

 Continued…

Figure2.7 Northbridge and Southbridge Connectivity

114
 Bus & Bus Speed

◉ In electronics, you can think of a bus as an electronic highway on

which data travels. The bus is a circuit that connects one part of
the motherboard to another.
○ With computers there has to be a communication highway
between the CPU and other parts.
◉ When shopping for a computer or a motherboard you're almost
certain to see the speed listed as something like "1333 MHz“ or
“1.3GHz”.
◉ This is the front side bus speed, also known as the motherboard
speed. It is how fast data travels between the CPU and memory
and is measured in megahertz (MHz) or Gigahertz.
115
 Expansion Slots

◉ Modern day computers come with audio, video, and other features
built right into the motherboard.
◉ If you don't want to use these, expansion slots give you the
flexibility to choose and have your own audio, video, or other card
installed.
◉ The number of slots varies according to the manufacturer and
model.

116
 4. Evolution of Motherboard

1981 The first motherboard, originally called a "planar," was used in

the IBM Personal Computer.

1984 The AT, or Full AT, motherboard form factor was introduced by IBM in
August 1984.

1985 IBM introduced the Baby AT motherboard form factor in 1985.

1987 The LPX motherboard form factor was developed by Western Digital in
1987.

1995 Intel released the first version of the ATX specification for motherboards
in July 1995.

117
 Continued…

1997 The first motherboards with AGP support are released in August
1997 by Intel and November 1997 by FIC.

1998 Intel introduced the WTX motherboard form factor in September

1998.

1999 Intel introduced the FlexATX motherboard form factor in 1999.

2000 Kontron introduced the ETX motherboard specification in early

2000.

2001 The UTX motherboard form factor was introduced by TQ-

Components in 2001.

118
 Continued…

2003 The PCI Express standard was introduced in 2003 by the PCI-SIG.
Motherboards with a PCI Express slot were released later the same year.

2003 The Nano-ITX form factor for motherboards was introduced in March 2003.

2004 NVIDIA introduced their SLI technology in 2004, allowing the ability to link
two video cards together on a motherboard.

2004 Intel released the BTX form factor and specification for motherboards in
February 2004. The microBTX and PicoBTX form factors were also
released the same year.

2004 The Mobile-ITX form factor for motherboards was introduced in March
2004.
2005 The PICMG, a group of over 150 companies, introduced the COM Express
form factor in 2005.
119
 Continued…

2005 The XTX motherboard form factor and specification was released in 2005.

2006 Using two video cards with a microATX motherboard became possible in 2006
for computer gamers.

2006 Supermicro released the SWTX motherboard form factor in 2006.

2007 The Pico-ITX form factor for motherboards was introduced in April 2007.

2007 AMD developed the DTX form factor in January 2007. AMD also developed and
released the Mini-DTX form factor in 2007.

2010 EVGA released the HPTX motherboard form factor in 2010.

120
 5. Removing and replacing motherboard

◉ When upgrading a motherboard or processor, several

issues must be taken into account.

◉ The following list guides a technician through making

the decision (or helping a customer make the
decision) of whether to upgrade a motherboard.

121
 Continued…

◉ Why is the computer being upgraded?

○ For example,
■ Does the computer need more memory?
■ Are more expansion slots needed?
■ Does the computer need a bigger/faster CPU to run
certain operating systems or applications?
■ Sometimes upgrading the motherboard does not help
unless the other computer components are upgraded.
■ The most expensive and fastest motherboard will not
run applications well unless it has the proper amount of
memory.
122
 Continued…

◉ Which type (ISA, PCI, AGP, or PCI-E)?

○ How many adapters are needed from the old
motherboard?
○ Does the new motherboard have the required
expansion slots?
◉ Could any devices, such as the hard drive or CD or DVD drive
that currently require an adapter, plug directly into the
upgraded motherboard? If so, it would free up expansion slots
as well as speed up the devices.
123
 Continued…

◉ What type of chipsets does the new motherboard

support?
○ What features, if any, would this bring to the new
motherboard?
◉ Will the new motherboard fit in the current computer
case or is a new one required?
◉ If upgrading the CPU, will the motherboard support
the new type of CPU?
124
 Continued…

◉ Does the motherboard allow for future CPU

upgrades?
◉ How much memory (RAM) does the motherboard
allow?
○ What memory chips are required on the new
motherboard?
○ Will the old memory chips work in the new
motherboard or with the new CPU?
125
 Continued…

◉ Before replacing a motherboard, keep the following

list in mind:
○ Remove adapters from expansion slots
○ Remove memory chips from expansion slots
○ Disconnect power connectors
○ Disconnect ribbon cables
○ Disconnect external devices such as mouse,
keyboard, and monitor.
126
 Continued…

◉ Replacement motherboards do not normally come

with RAM, so the old ones are removed from the bad
motherboard.
◉ The motherboard may or may not come with a CPU.
◉ Make note of the CPU orientation before removing it
from the motherboard.
◉ When installing the CPU into the replacement
motherboard, refer to these notes.
127
 6. Troubleshooting the Motherboard

◉ Motherboards and power problems are probably the

most difficult things to troubleshoot.
◉ Because various components are located on the
motherboard, many things can cause an error.
◉ POST is one of the most beneficial aids for
troubleshooting the motherboard.
◉ The meaning of any codes that appear on the screen
should be researched.
128
 Continued…

◉ The following list helps with motherboard

troubleshooting:
○ Is the motherboard receiving power?
■ Check the power supply to see if the fan is
turning.
■ If the CPU or motherboard has a fan, see if it is
turning.
■ Check voltages going from the power supply
to the motherboard.
129
 Continued…

○ Check the BIOS settings for accuracy.

○ Check the motherboard jumper or BIOS settings to
see if they have been changed or ask the user if
they have changed anything in the BIOS.
○ Check for overheating.
■ Power down the computer and allow the
computer to cool.
■ Power on the computer with the cover off.
○ Reseat the CPU and memory chip.
130
 Continued…

○ Remove unnecessary adapters and boot.

○ Plug the computer into a different power outlet and
circuit if possible.
○ Check if the motherboard is shorting out on the
frame.
○ Check the CMOS battery
○ Some motherboards have diagnostic LEDs.
■ Check the output for any error code.
■ Refer to the motherboard documentation or online
documentation for the problem and possible solution
131
THE END OF CHAPTER TWO

132
CHAPTER THREE
CPU

133
 List of Contents

◉ Introduction
◉ History of CPU
◉ Types of CPU
◉ CPU Sockets and slots
◉ Upgrading CPUs

134
 1. Introduction

◉ At the heart of every computer is a special

motherboard chip called the processor
◉ It determines, to a great extent, the power of the
computer.
◉ The processor is also called the CPU (central
processing unit) or microprocessor.
◉ The CPU executes instructions, performs math
calculations, and coordinates input/output operations.
135
 Continued…

◉ The major processor manufacturers today are Intel,

Motorola, VIA, and AMD (Advanced Micro Devices, Inc.).
◉ The processors designed by Motorola have been used
in Apple computers for years.
◉ Intel designed the processors IBM used in their first
computers.

136
 1.1 Processor Basics

◉ All processors use 1s and 0s. One 1 or one 0 is a bit.

◉ Eight bits grouped together are a byte.
◉ The letter A looks like 01000001 to the processor.
◉ Each character on a keyboard appears as one byte or
eight bits to the processor.
◉ Approximately 1,000 bytes is a kilobyte (kB). (1,024
bytes to be exact, but the computer industry rounds off
the number to the nearest thousand for ease of
calculation.)
137
 Continued…

◉ Microprocessors come in a variety of speeds.

◉ The speed of processors is measured in gigahertz
(GHz).
◉ Hertz is a measurement of cycles per second.
◉ One hertz equals one cycle per second.
◉ One gigahertz is one billion cycles per second or 1GHz.
◉ Older CPUs used megahertz (MHz) as the standard
measurement.
138
 Continued…

◉ One megahertz is one million cycles per second or

1MHz.
◉ The original PC CPU, the 8088 microprocessor, ran at
4.77MHz.
◉ Today’s microprocessors run at speeds over 3GHz.
◉ The number of bits processed at one time is the
microprocessor’s register size (word size).
◉ Register size is in multiples of 8 bits (i.e., 8-, 16-, 32-, 64-
, or 128-bit).
139
 Continued…

◉ Intel’s 8086 processor’s register size was 16 bits or two

bytes.
◉ Today’s CPUs have register sizes of 64 or 128 bits.
◉ The 1s and 0s must travel from one place to another
inside the processor as well as outside to other chips.
◉ To move the 1s and 0s around, electronic lines called a
bus are used.
◉ The electronic lines inside the CPU are known as the
internal data bus or system bus
140
 Continued…

◉ In the 8086 the internal data bus comprises 16

separate lines with each line carrying one 1 or one 0.
◉ The word size and the number of lines for the internal
data bus are equal.
◉ The 8086, for example, had a 16-bit word size, and 16
lines carried 16 bits on the internal data bus.
◉ In today’s microprocessors, 64 or 128 internal data bus
lines operate concurrently.

141
 Continued…

◉ For the CPU to communicate with devices in the

outside world, such as a printer, the 1s and 0s travel on
the external data bus.
◉ The external data bus connects the processor to
adapters, the keyboard, the mouse, the floppy drive,
the hard drive, and other devices.
◉ The external data bus is also known as the external
data path.

142
Continued…

Figure 3.1 Internal and external data buses

143
 Continued…

◉ Processors have a special component called the ALU

(arithmetic logic unit), which does all the calculations and
comparison logic needed by the computer.
◉ Today’s processors actually have two ALUs.
◉ The control unit coordinates activities inside the processor.
◉ The I/O unit manages data entering and leaving the
processor.
◉ The registers within the CPU are a very high speed
storage area for 1s and 0s before the bits are processed.
144
 2. History of CPU

◉ Moore’s Law observes that the number of transistors on

a chip doubles every two years.
◉ Based on this law, the development of the computer
processors started in the year 1971.
◉ The first computer that was used was developed at the
University of Pennsylvania in the year 1946! It had an
ENIAC (Electronic Numerical Integrator And Computer)
processor.

145
 Continued…

◉ The reprogramming feature that is so extensively used

today, was introduced by Alan Turing and John von
Neumann with their teams.
◉ 1971 – Intel 4004
○ It consisted of 2300 transistors with pMOS
technology.
○ The total number of instructions were 46.
○ The designed clock speed was 1 MHz while only 740
kHz was achieved.
146
 Continued…

◉ 1972 – Intel 8008

○ It was made up of 3500 transistors.
○ The clock speed was 0.5 MHz.
○ The total number of instructions were 48.
◉ 1974 – Intel 8080
○ The clock speed increased to 2 MHz,
○ It was built on nMOS technology and used 6000
transistors.
○ separation of address (16-bit) and data (8-bit) bus.
○ It also supported 256 I/Os.
147
 Continued…

◉ 1974 – Motorola 6800

○ This processor developed by Motorola had no I/O ports.
○ Memory-mapped input-output were used as I/Os.
○ The clock speed was only 2 MHz with the instruction set
consisting of 72 instructions.
◉ 1979 – Intel 8088
○ Based on the new HMOS technology
○ The designed frequency was 10 MHz.
○ The data path was only 8-bit.

148
 Continued…

◉ 1987 – SPARC
○ This processor was developed by Sun Microsystems.
○ It had a clock speed of 40 MHz.
○ It was made up of 1.8 million transistors with 256 I/O pins.
◉ 1991 – Am386
○ This AMD (Advanced Micro Devices) processor had striking
resemblance to the Intel 80386 version x86 processors.
○ With a clock speed of 40 MHz and 32-bit data bus, the
processor was a competitor to Intel.

149
 Continued…

◉ 1993 – Pentium Processor

○ The Pentium family started with the launch of the P5
processor.
○ It came in two models – 510-pin version with 60 MHz
clock speed and 567-pin version with a clock speed of
66 MHz.
○ It was built with 3.1 million transistors.

150
 Continued…

◉ 1999 – Athlon
○ Developed by AMD
○ It was built using 37 million transistors and achieved a
clock speed of about 800 MHz.
○ It was packaged in a unique PGA (Pin Grid Array) 453-
pin packaging.
○ It was the first processor to reach the speed of 1 GHz.

151
 Continued…

◉ 2003 – Pentium M
○ This processor was a mobile single-core processor
from Intel.
○ It was designed with a clock speed of 2.26 GHz.
◉ 2006 – Core 2
○ The clock speed was achieved up to 3.5 GHz.
○ The processors launched under this family were
single-core, dual-core and quad-core.

152
 Continued…

◉ The latest-Sandy Bridge

○ It has achieved a 32-nanometer die manufacturing.
○ It includes Intel Quick sync that is a hardware support
for video encoding and decoding.
○ The transistor count used in this processor reaches up
to 2.27 billion.
○ The clock speed designed is 3.6 GHz.

153
 3. Types of CPU

◉ Intel processors
○ Intel CPUs are used most frequently in PC builds and
smaller companies.
○ Traditionally, Intel has rated its processors by GHz and people
have compared processors based on speed alone.
○ Now, Intel arranges its products by family numbers.
○ Within a family of microprocessors, you can compare things
such as speed and the amount of cache memory and other
technologies within the family.

154
 Continued…

Table 3.1 Intel processor families

155
 Continued…

◉ AMD CPUs
○ AMD CPUs are most often used in servers and
workstation computers for bigger corporations.
○ They can be used in gaming computers as well, but
that isn’t as common.

156
 Continued…

Table 3.2 AMD processor families

157
 4. CPU Sockets and slots

◉ A processor inserts into a socket or slot depending on

the model.
◉ Most processors today insert into a socket.
◉ There are different types of sockets:
○ PGA (pin grid array), which has even rows of holes around
the square socket;
○ SPGA (staggered pin grid array), which has staggered
holes so more pins can be inserted;
○ PPGA (plastic pin grid array) used on Intel Celerons and
Pentium 4s;
158
 Continued…

○ μPGA (micro pin grid array) used by AMD; and

○ LGA (land grid array) used with AMD and Intel
processors.
◉ The processor sockets used today are called ZIF
sockets (zero insertion force);
◉ Even though people call all sockets with a lever a ZIF
socket, they come in different sizes, depending on the
processor installed.

159
Continued…

Figure 3.3 LGA775 socket

160
 5. Upgrading CPUs

◉ Whenever a processor is purchased, it includes

installation instructions.
◉ Also, motherboard manuals (documentation) include the
steps to upgrade or install the CPU.

Note: Always hold the CPU by the edges to avoid bending

or touching the pins underneath. Do not lay the CPU down
where the pins are on a flat surface because they can easily
bend.
161
 Continued…

◉ The general steps for installing a processor:

1. Be sure power to the computer is off and the
computer is unplugged.
2. Place the antistatic wrist strap around your wrist and
attach the other end to a ground on the computer.
3. Remove the old processor by lifting the ZIF(zero
insertion force) socket retaining lever.
4. Insert the CPU into the socket. When installing a CPU,
it fits only one way into the socket.
162
 Continued…

Look at the processor and the socket before inserting the

chip to ensure proper alignment. A socket and CPU
normally have a triangle marking or circular dot that
shows where pin 1 goes.

If the socket has a retention lever, raising the socket lever

allows a CPU to be inserted. Lowering the lever keeps the
CPU inserted into the socket.

163
 Continued…

5. Normally, you must configure the motherboard by

jumpers or through BIOS software configuration.
Refer to the motherboard manual for exact steps.

If needed, set any jumpers or switches on the

motherboard necessary for proper operation or press
the correct key to enter the setup program that allows
you to set the CPU speed and proper multiplier.

164
Continued…

Figure 3.2 Installing an AMD CPU

165
 Continued…

◉ Two common questions asked of technicians are:

1. “Can a computer be upgraded to a higher or faster
processor?” and
2. “Should a computer be upgraded to a higher or faster
processor?”

○ Whether or not a computer can be upgraded to a

higher or faster processor depends on the capability of
the motherboard.
166
 Continued…

○ When a customer asks if a processor should be

upgraded, the technician should ask, “What operating
system and applications are you using?”
○ The newer the operating system, the more advanced
a processor should be.
○ When installing multiple processors, some
motherboards require that the same processor model
is used in each slot.
○ This is not always true with the newer motherboard.
167
 Continued…

◉ When upgrading a CPU on an older or newer system, an

important consideration is CPU voltage.
◉ Nowadays, a VRM (voltage regulator module) is
integrated into the motherboard and can provide the
appropriate voltage.
◉ Throttle management is the ability to control the CPU
speed by slowing it when it is not being used heavily or is
running too hot.
○ Usually this feature is controlled by a system BIOS setting.
168
 Continued…

◉ Important tips
○ Do not upgrade the processor unless the documentation or
manufacturer states that the motherboard supports a newer or
faster processor.

○ After installing CPU do not apply power to the computer until

the CPU and the heat sink, fan, and/or cooling unit are installed.
Running the CPU without cooling it will overheat the CPU and
destroy or weaken it.

169
THE END OF CHAPTER THREE

170
CHAPTER FOUR
Memory

171
 List of contents

◉ Introduction
◉ Types of memory
◉ Random Access Memory defined
◉ Read-only Memory and Cache Memory
◉ Physical memory packaging
◉ Identify Memory Problems and upgrading

172
 1. Introduction

◉ Computer memory is the storage space in the

computer, where data is to be processed and
instructions required for processing are stored.

◉ Computer systems need software to operate;

◉ For the computer to operate, the software must
reside in computer memory.

173
 1. Introduction

◉ The memory is divided into large number of small

parts called cells.
◉ Each location or cell has a unique address, which
varies from zero to memory size minus one.
○ For example, if the computer has 64k words, then
this memory unit has 64 * 1024 = 65536 memory
locations.
○ The address of these locations varies from 0 to
65535. 174
 2. Types of Memory

◉ Although many types of memory in a computer exist,

○ the most basic distinction is between
■ primary memory, often called system
memory, and
■ secondary memory, which is more commonly
called storage.

175
 Continued…

◉ Primary memory
○ includes ROM and RAM, and is located close to
the CPU on the computer motherboard, enabling
the CPU to read data from primary memory very
quickly indeed.
○ It is used to store data that the CPU needs
imminently so that it does not have to wait for it to
be delivered.

176
 Continued…

◉ Secondary memory
○ by contrast, is usually physically located within a
separate storage device, such as a hard disk drive
or solid state drive (SSD), which is connected to
the computer system either directly or over a
network.
○ The cost per gigabyte of secondary memory is
much lower, but the read and write speeds are
significantly slower.
177
 Continued…

MEMORY

Primary Secondary
memory memory

RAM ROM

PROM Floppy Magnetic

SRAM DRAM EEPROM HDD SDD CD
EPROM Disk tap

178 Figure 4.1 Types of Memory

 3. Random Access Memory (RAM)

◉ RAM is found on the motherboard and stores the

operating system, the software applications, and the
data being used by all of the software.
◉ RAM is also found on adapters such as video cards.
◉ RAM is volatile memory; the information in RAM is lost
when you power off the computer.
◉ RAM is divided into two major types:
○ DRAM (dynamic RAM) and
○ SRAM (static RAM).
179
 Continued…

◉ DRAM is less expensive, but slower than SRAM.

◉ With DRAM, the 1s and 0s inside the chip must be
refreshed.
◉ Over time, the charge, which represents information
inside a DRAM chip, leaks out.
◉ The information, stored in 1s and 0s, is periodically
rewritten to the memory chip through the refreshing
process.
180
 Continued…

◉ The refreshing is accomplished inside the DRAM while

other processing occurs.
◉ Refreshing is one reason DRAM chips are slower than
SRAM.
◉ Most memory on the motherboard is DRAM, but a
small amount of SRAM can be found on a motherboard
or, as is the norm for today’s computers, inside the
microprocessor.

181
 Continued…

◉ SRAM is also known as cache memory.

◉ The cache memory holds the most frequently used
data so the CPU does not return to the slower DRAM
chips to obtain the data.
◉ For example, on a motherboard with a bus speed of
100MHz, accessing DRAM could take as long as 180
nanoseconds.
◉ Accessing the same information in cache could take as
little as 45 nanoseconds.
182
 Continued…

◉ The data or instruction that the microprocessor needs is

usually found in one of three places:
○ cache, DRAM, or the hard drive. Cache gives the fastest access.
○ If the information is not in cache, the microprocessor looks for
it in DRAM.
○ If the information is not in DRAM, it is retrieved from the hard
drive and placed into DRAM or the cache.
○ Hard drive access is the slowest of the three.
○ In a computer, it takes roughly a million times longer to access
information from the hard drive than it does from DRAM or
cache.
183
 Continued…

◉ When determining a computer’s memory requirements,

you must take into consideration the operating system
used, applications used, and hardware installed.
◉ The Windows 98 operating system takes a lot less
memory than the Windows XP or Vista.
◉ High-end games and desktop publishing take more
RAM than word processing.

NOTE: RAM is only one piece of the puzzle. All of the computer’s
parts must work together to 184
provide good system performance
 4. Read Only Memory (ROM)

◉ ROM is nonvolatile memory; the information is in ROM

even when the computer is powered off.
◉ ROM chips can also be found on adapters including
SCSI, network, and video cards.
◉ The software contained inside the ROM chip is allowed
to execute during the boot process and initialize the
adapter and possibly detect devices attached to the
adapter.

185
 Continued…

◉ ROM is mainly classified as:

○ Programmable read only memory (PROM)
■ Can be modified only once by a user
○ Erasable programmable read only memory (EPROM)
■ Can be erased and reused.
○ Electric erasable read only memory (EEROM)
■ Can be erased and reprogrammed repeatedly
through a normal electrical voltage.

186
 5. Physical Memory Packaging

◉ A DIP (Dual In-line Package) chip has a row of legs

running down each side.
◉ The oldest motherboards use DIP chips for the DRAM.
◉ SIMMs (Single In-line Memory Modules) came along
next.
◉ Two types of SIMMs were used: 30-pin and 72-pin.
◉ The memory chip used today is a DIMM (Dual In-line
Memory Module), which has 168, 184, or 240 pins.
187
Continued…

Figure 4.2 Memory chips

188
 Continued…

◉ Memory chips are also called memory sticks, or a

technician might call one memory module a stick of
memory or RAM.
◉ RIMMs are used in older Intel Pentium 4 computers.
◉ The figure on the next slide illustrates these types.
◉ Notice the single notch at the bottom of the 184-pin
DDR DIMM.
◉ This distinguishes it from the other dual-notched
DIMMs. 189
Continued…

Figure 4.3 184-pin DDR DIMM and RIMM

190
 Continued…

◉ NOTE: Memory module contacts are either tin or gold

(although most are gold). If the computer is designed to
accept tin memory modules and you install gold ones,
over time a chemical reaction between the metals can
damage the connector. Memory errors also occur.
◉ Be certain to purchase the appropriate memory module
for the computer by referring to the documentation or
by examining other chips already installed.

191
 6. Identify Memory Problems and upgrading

◉ You can get “out of memory” errors, system slowdowns,

or application locking due to memory problems with any
operating system.
◉ No matter which operating system is being used, check
the amount of free space on the hard drive.
◉ Sometimes you must close all applications, reboot the
computer, and open only the application that was
running when the error occurred because some
applications do not release the memory space they hold.
192
 Continued…

◉ Memory troubleshooting and managing steps:

○ Add more RAM.

○ If you just installed new memory and an error appears, this is

normal. Enter Setup, the BIOS knows something has changed.

○ If you just installed new memory and the computer will not
boot, check your installation by pushing harder on the memory
module to ensure that it is fully seated into the slot. Check for
loosened cables that you might have caused. Ensure that you
are installing the right memory type.
193
 Continued…

○ Delete files/applications that are no longer needed and close

applications not being used.
■ Empty the Recycle Bin.
○ Adjust virtual memory size.

○ Change the virtual memory settings so that it uses more hard

drive space.

○ Do not put the swap file on multiple partitions that reside on

the same hard drive.
■ Use multiple hard drives if necessary.
194
 Continued…

○ Put the swap file on a hard disk partition that does not contain
the operating system.

○ Put the swap file on the fastest hard drive.

○ Remove the desktop wallpaper scheme or use a plain one

○ Adjust your Temporary Internet Files setting.

○ Defragment the hard drive.

195
 Continued…

○ If you receive a message that the SPD (serial

presence detect) device data missing or
inconclusive, your motherboard is looking for SPD
data that it cannot receive from the memory
module.
■ If this is a new module, ensure it supports SPD.
■ If it is an older module, you need to replace one
of your memory modules.

196
 Continued…

○ POST usually detects a problem with a memory

chip, and most BIOS chips show an error code or
message.
■ If POST issues a memory error, turn off the
computer, remove the cover, and press down on
any memory modules and reboot.
■ Another option is to clean the memory module
slots with compressed air and reinstall the
module.
197
 Continued…

◉ Note Today’s operating systems rely almost as much

on hard drive space as they do RAM because of the
multitasking. Lack of hard drive space is almost as bad
as not having enough RAM. Also, not all applications
can use available memory. Whether or not an
application can use all the RAM in a system depends on
the operating system/environment installed on the
computer and the operating system for which the
application is written.
198
 6.1 Installing or Upgrading Memory

◉ Now you know more about memory. Let us look at the

practical side, how do you go about planning a memory
installation.
◉ Some key points to consider are:
○ Refer motherboard documentation to see what type of
memory is supported
○ Determine what features are supported
○ Determine how much memory is needed
○ Determine how many of each memory module is needed
○ Research prices and purchase memory module(s)
199
 Continued…

◉ Removing/Installing a DIMM/RIMM:
○ When removing a DIMM or a RIMM and using proper ESD
prevention techniques, push down on the DIMM retaining tabs
that clasp over the DIMM.
○ Be careful not to overextend the tabs when pushing on them.

○ If a plastic tab breaks, the only solution is to replace the

motherboard.
○ The DIMM/RIMM lifts slightly out of the socket.
○ Ensuring you are grounded to prevent ESD, lift the module out
of the socket once it is released.
200
 Continued…

Figure 4.5 DIMM/RIMM removal Figure 4.5 DIMM/RIMM installation

201
THE END OF CHAPTER FOUR

202
CHAPTER FIVE
Power Supply

203
 List of contents

◉ Power supplies
◉ Types of power supply
◉ Power supply form factors
◉ Laptop Power
◉ Troubleshooting the Power Supply

204
 1. Introduction to Power Supplies

◉ The power supply is an essential component within

the computer;
◉ No other internal computer device works without it.
◉ The power supply:
○ Converts AC to DC,
○ Distributes lower voltage DC power to
components throughout the computer,
○ Provides cooling through the use of a fan located
inside the power supply.
205
 Continued…

◉ The power supply is sometimes a source of unusual

problems.
◉ The effects of the problems can range from those not
noticed by the user to those that shutdown the
system.

206
 2. Types of Power Supply

◉ AC power supplies come in two varieties,

unregulated and regulated.

◉ Unregulated is the most basic type of power supply

and does not have the ability to supply consistent
voltage to a load, while regulated power supplies do
and have many different design options.

207
 Continued…

◉ Unregulated power supply

○ Because unregulated power supplies do not have
voltage regulators built into them, they typically are
designed to produce a specific voltage at a specific
maximum output load current.
○ These are typically the block wall chargers that turn
AC into a small trickle of DC and are often used to
power devices such as household electronics.
○ They are the most common power adapters and are
nicknamed a “wall wart”.
208
 Continued…

○ With an unregulated DC power supply, the voltage

output varies with the size of the load.
○ It typically consists of a rectifier and capacitor
smoothing, but no regulation to steady the voltage.
○ It may have safety circuits and would be best for
applications that do not require precision.

209
 Continued…

◉ REGULATED POWER SUPPLY

○ A regulated DC power supply is essentially an
unregulated power supply with the addition of a voltage
regulator.
○ This allows the voltage to stay stable regardless of the
amount of current consumed by the load, provided the
predefined limits are not exceeded.
○ In regulated power supplies, a circuit continually samples
a portion of the output voltage and adjusts the system to
keep the output voltage at the required value.
210
 Continued…

○ In many cases, additional circuitry is included to

provide current or voltage limits, noise filtering, and
output adjustments.

○ There are three subsets of regulated power

supplies: linear, switched, and battery-based.

211
 Continued…

○ Linear Power Supply

■ Linear power supplies are used when precise
regulation and the removal of noise is most important.
■ While they are not the most efficient power source,
they provide the best performance.
■ The name is derived from the fact that they do not
use a switch to regulate the voltage output.
■ Compared to switched power supplies and batteries,
they are also less efficient, sometimes exhibiting only
50% efficiency.
212
 Continued…

○ Switched Power Supply

■ Switched mode power supplies (SMPS) are more
complicated to construct but have greater
versatility in polarity and, if designed properly,
can have an efficiency of 80% or more.
■ Although they have more components, they are
smaller and less expensive than linear power
supplies.
■ One of the advantages of switched mode is that
there is a smaller loss
213
across the switch.
 Continued…

■ A computer uses a switching power supply.

■ It provides efficient power to all the computer’s
internal components (and possibly to some
external ones, such as USB devices).
■ It also generates minimum heat, comes in small
sizes, and is cheaper.

214
 Continued…

○ Battery-based
■ It is essentially a mobile energy storage unit.
■ Battery-based power produces negligible noise
to interfere with electronics, but loses capacity
and does not provide constant voltage as the
batteries drain.
■ In most applications using laser diodes, batteries
are the least efficient method of powering the
equipment.
215
 Continued…

■ Most batteries are difficult to match the correct

voltage to the load.
■ Using a battery that can exceed the internal
power dissipation of the driver or controller can
damage your device.

216
 3. Power Supply Form Factors

◉ Just as motherboards come in different shapes and

sizes, so do power supplies.
◉ Today’s power supply form factors are:
○ ATX, ATX12V v1.x, and ATX12V v2.x.
○ Other form factors include:
■ LFX12V (low profile),
■ SFX12V (small form factor),
■ EPS12V (used with server motherboards and has
an extra 8-pin connector),
217
 Continued…

■ CFX12V (compact form factor),

■ TFX12V (thin form factor),
■ WTX12V (workstation form factor for high-end
workstations and select servers), and
■ FlexATX (smaller systems that have no more than
three expansion slots).

218
Continued…

219 Figure 5.1 ATX power supply

 Continued…

◉ The number and quantity of connectors available on a

power supply depends on the power supply
manufacturer.
◉ If a device requires a Berg connector and the only one
available is a Molex, a Molex-to-Berg connector
converter can be purchased.
◉ The power supply connectors can connect to any
device; there is not a specific connector for the hard
drive, the CD/DVD drive, and so on.
220
 Continued…

◉ If there are not enough connectors from the power

supply for the number of devices installed in the
computer, a Y power connector can be purchased at a
computer or electronics store.
◉ The Y connector adapts a single Molex connector to
two Molex connectors for two devices.

221
 Continued…

Figure 5.2 Molex-to-Berg and Molex-to-SATA converters

222
 Continued…

Figure 5.3 Y Molex connector

223
 4. Laptop Power

◉ A portable computer (laptop) uses either an AC

connection or a battery as its power source.

◉ On most models, when the laptop connects to AC

power, the battery normally recharges.

◉ Laptop batteries are usually modules with one or two

release latches that are used to remove the module.
224
 Continued…

◉ Battery technologies have improved in the past few years,

probably due to the development of more devices that need
battery power, such as digital cameras, portable CD and DVD
players, and PDAs (personal digital assistants).
◉ Until 1996 the NiCad (nickel cadmium) battery was the most
popular type of portable computer battery.
◉ NiCad batteries were said to be subject to a memory effect,
which means that the battery could not be fully recharged if
it was not fully drained.
◉ In reality, the NiCad battery memory effect is rare.
225
 Continued…

◉ NiCad batteries were replaced with lighter and more powerful

NiMH (nickel-metal hydride) batteries.
◉ These batteries were replaced with Li-ion (lithium-ion) batteries,
which are very light and can hold a charge longer than any other
type.
◉ They are also more expensive.
◉ Besides laptops, mobile phones, portable media players, and
digital cameras use Li-ion batteries.
◉ Li-ion batteries lose their charge over time even if they are not
being used.
226
 Continued…

◉ Use your laptop with battery-provided power.

◉ Do not keep a laptop that has an Li-ion battery plugged into an AC
outlet all the time.
◉ Calibrate a laptop battery according to manufacturer instructions
so the battery meter displays correctly.

◉ NOTE: Li-ion batteries last longer if they are kept cool (not frozen).
If storing an Li-ion battery, the battery should only be 40 percent
charged and placed in a refrigerator to prolong its life.

227
 5. Troubleshooting the Power Supply

◉ When you suspect the power supply is the problem, swap the
power supply, make the customer happy, and be on your way!
◉ Power problems are not usually difficult to detect or troubleshoot.
◉ Do not overlook the most obvious power supply symptom.
◉ Start by checking the computer power light.
◉ If it is off, check the power supply’s fan by placing your palm at the
back of the computer.
◉ If the fan is turning, it means the wall outlet is providing power to
the computer and you can assume that the wall outlet is
functioning.
228
 Continued…

◉ Test the power outlet with another device.

◉ Ensure the power cord is inserted fully into the wall outlet and the
computer.
◉ If you suspect the wall outlet, use an AC circuit tester to verify the
wall outlet is wired properly.
◉ On a laptop that is running on battery power, check the laptop
battery charge icon through the operating system.
◉ If it works on AC power, try recharging the battery.
◉ If the battery does not recharge, replace it.

229
 Continued…

◉ Twist the AC power to see if the connection is loose.

◉ Remove the laptop battery for a moment and then re-insert it (and
attach AC power if battery power does not work).
◉ See if the power brick has a power light on it and whether it is lit.
◉ Try a different AC adapter from the same manufacturer because
AC adapters are proprietary between laptop vendors

230
 5.1 Symptoms of Power Supply Problems

◉ The following list offers symptoms of a power supply problem:

○ The computer power light is off.
○ The power supply fan does not turn when the computer is
powered on.
○ The computer sounds a continuous beep (this could also be a
bad motherboard or a stuck key on the keyboard)
○ When the computer powers on, it does not beep at all (this
could also be a bad motherboard)
○ When the computer powers on, it sounds repeating short
beeps (this could also be a bad motherboard)

231
 Continued…

○ During POST, a 02X or parity POST error code appears (where

X is any number); one of the POST checks is a power good
signal from the power supply; a 021, 022, . . . error message
indicates that the power supply did not pass the POST test.
○ The computer reboots without warning
○ The power supply fan is noisy
○ The power supply is too hot to touch
○ The monitor has power light, but nothing appears on the
monitor and no PC power light illuminates

232
THE END OF CHAPTER FIVE

233
CHAPTER SIX
Storage Devices

234
 List of contents

◉ The Floppy Drive

◉ The Hard Drive
◉ The CD-ROM Drive
◉ Troubleshooting storage devices

235
 1. The Floppy Drive

◉ The floppy drive is the device that allows saving data to

disk media.
◉ The floppy drive subsystem consists of three main
parts:
1. The electronic circuits or the controller,
2. The 34-pin ribbon cable, and
3. The floppy drive (sometimes called the “a” drive).

236
 Continued…

◉ The electronic circuits give the floppy drive instructions:

○ “Floppy drive, go to this location and read some
data!
○ Floppy drive, go to this other location and write
some data!”
○ The electronic circuits can be on an adapter or built
into the motherboard.

237
 1.1 Floppy Media and Construction

◉ The media inserted in a floppy drive is a disk or floppy

disk.
◉ On one side, a disk has a sliding write protect window
that allows the disk to be written to or protected from
any writing or changing of data that is occurring.
◉ If you close the window, data can be written to the disk.
◉ If the window is open, the disk is write-protected and
data cannot be written on the disk.

238
 Continued…

◉ Floppy drives have two read/write heads responsible

for placing the data, the 1s and 0s, onto the disk.
◉ The disk inserts between the two heads of the floppy
drive.
◉ One read/write head mounts on the top, the other on
the bottom.

239
 1.2 Floppy Drive Installation or Replacement

◉ Installation of floppy drives is simple after doing the

following preliminary homework:
○ An available drive bay
○ An available power connection 34-pin floppy
connector
○ A motherboard floppy connector or install an
additional adapter
○ A floppy cable

240
 Continued…

Figure 6.1 Floppy connector on motherboard

241
 Continued…

◉ The floppy cable is unique to the computer because

of the twist at the end of the cable that attaches to
the floppy drive.
◉ Keep in mind the end with the twist is the one that
connects to the drive.

242
Figure 6.2 Floppy drive cable
 Continued…

◉ Pin 1 on the cable needs to attach to pin 1 on the connector.

◉ Pin 1 on a cable is easy to find because of the colored stripe
that is on one side of the cable.
◉ Some manufacturers put a small 1 or 2 by the end where
the cable’s pin 1 inserts.
◉ Other manufacturers put larger numbers at the opposite
end.
◉ For example, if you see the number 33 or the number 34 on
the motherboard where the floppy cable inserts.
243
 Continued…

◉ NOTE
◉ Attach cable correctly or destroy devices and
components
○ Devices, adapters, controlling circuits, and so on,
can be damaged if a cable plugs into the connector
the wrong way. Some cables are keyed so they
insert only one way into the connector. Most cables
that connect to the floppy drive are keyed, but the
other end of the cable that connects to the
controlling circuits is sometimes
244 not keyed.
 2. The Hard Drive

◉ Hard drives are one of the most popular devices for

storing data.
◉ They store more data than floppy drives and move
data faster than tape drives.
◉ Today’s hard drive capacities extend into the terabytes.
◉ Hard drives are frequently upgraded in a computer, so
it is important for you to understand all the technical
issues.

245
 Continued…

◉ These issues include:

○ knowing the parts of the hard drive subsystem,
○ How the operating system and the BIOS work with a
hard drive,
○ How to configure a hard drive, and how to troubleshoot
it.
◉ The hard drive subsystem can have up to three parts:
1. The hard drive;
2. A cable that attaches to an adapter or the motherboard;
and
3. Control circuits located 246
on an adapter or the motherboard.
 2.1 Hard Drive Geometry

◉ Hard drives have multiple hard metal surfaces called

platters.
◉ Each platter typically holds data on both sides and has
two read/write heads, one for the top and one for the
bottom.
◉ The read/write heads float on a cushion of air without
touching the platter surface. If a read/write head
touches the platter, a head crash occurs.
◉ This is sometimes called HDI (head to disk interference).
247
 Continued…

Figure 6.3 Hard drive geometry Figure 6.4 Seagate Barracuda hard drive
248
 Continued…

◉ Each hard drive surface is metallic and has concentric

circles, each of which is called a track.
◉ Tracks are numbered starting with the outermost track,
which is called track 0.
◉ One corresponding track on all surfaces of a hard drive
is a cylinder.
◉ Each track is separated into sectors by dividing the
circle into smaller pieces.
◉ 512 bytes are normally stored in each sector.
249
 Continued…

Figure 6.6 Hard drive sectors

Figure 6.5 Cylinders versus tracks 250
 2.2 Hard Drive Interfaces

◉ A hard drive system must have a set of rules to operate.

◉ These rules specify:
○ the number of heads on the drive,
○ what commands the drive responds to,
○ the cables used with the drive,
○ the number of devices supported,
○ the number of data bits transferred at one time, and
so on.

251
 Continued…

◉ These rules make up a standard called an interface that

governs communication with the hard drive.
◉ There are two major hard drive interfaces:
○ IDE (integrated drive electronics), also known as the
ATA (AT Attachment) standard, and
○ SCSI (small computer system interface).
◉ IDE is the most common in home and office computers.
◉ SCSI is commonly found in network servers.

252
 Continued…

◉ Both IDE and SCSI started out as parallel architectures.

◉ This means that multiple bits are sent over multiple
paths.
◉ This architecture requires precise timing as transfer
rates increase.
◉ With parallel IDE, it was only two devices and with SCSI
it was more, but the concept is the same.

253
 Continued…

◉ Today, there is a trend toward serial architectures.

◉ A serial architecture is a point-to-point bus where each
device has a single connection back to the controller.
◉ Bits are sent one bit at a time over a single link.
◉ More devices can attach to this type of architecture
because it scales easier and configuration is much
easier.

254
 Continued…

Figure 6.8 Serial transfer

Figure 6.7 Parallel transfer

255
 2.3 Storage Device Configuration

◉ Drive configuration sometimes includes setting jumpers

on the drive and sometimes on the associated adapter
and proper termination.
◉ Termination is a method used to prevent signals from
reflecting back up the cable.
◉ Each drive type has a normal configuration method.
◉ However, individual drive manufacturers may develop
their own configuration steps.

256
 2.3.1. PATA Physical Installation

◉ PATA IDE devices (including hard drives) are simpler to

configure than parallel SCSI devices.
◉ The overall steps for installing a PATA device are as
follows:
○ Keep the drive in the protective antistatic container
until you are ready to install
○ Use proper antistatic handling procedures when
installing the drive and handle the drive by the
edges; avoid touching the drive electronics and
connectors. 257
 Continued…

○ Turn off and remove the power cord when installing

the drive
○ Determine how many devices will attach to the same
cable and configure their jumpers accordingly.
○ Physically mount and secure the device in the
computer and attach the proper cable.
○ Configure the BIOS if necessary.
○ If a hard drive, prepare the drive for data.

258
Continued…

259 Figure 6.9 PATA motherboard connectors

 Continued…

◉ PATA IDE devices are normally configured using jumpers.

◉ The four options commonly found are single, master, slave, and
cable select.
◉ The single IDE setting is used when only one device connects to
the cable.
◉ The master IDE setting is used in conjunction with the slave setting
and both are used when two IDE devices connect to the same
cable.
◉ One device is set to the master setting while the other device uses
the slave setting.
◉ The cable select IDE option replaces
260 the master/slave setting.
Continued…

Figure 6.10 PATA device connectivity

261
 2.3.2 SATA Physical Installation

◉ SATA drives are easy to install.

◉ Most internal drives require a special host adapter that supports
one to four drives or an integrated motherboard connection.
◉ Each drive is seen as a point-to-point connection with the host
controller.
◉ SATA drives do not have any master/slave, cable select, or
termination jumpers or settings.
◉ A serial 7-pin connector attaches from the SATA controller to the
internal SATA drive.
◉ A longer cable connects power to the drive.
262
 Continued…

◉ To install a SATA host adapter, power off the computer and remove
the computer power cord.
◉ Remove the computer cover and locate an open expansion slot.
◉ Some adapters have jumpers for configurable options.
◉ Some common options include 16- and 32-bit PCI operations,
adapter BIOS enabled/disabled, and Mode 0 enabled/ disabled.
◉ Some adapters may provide master/slave emulation option.

263
Continued…

Figure 6.11 SATA connectivity

264
 2.3.3 Parallel SCSI Configuration

◉ Configure a parallel SCSI device by doing the following:

1. Setting the proper SCSI ID
2. Terminating both ends of the SCSI chain
3. Connecting the proper cable(s)
◉ The parallel SCSI chain consists of several SCSI devices cabled
together.
◉ The SCSI chain includes SCSI devices and a single controller,
sometimes called a host adapter.
◉ The SCSI controller is usually a separate adapter, but it may be
built into the motherboard.

265
 Continued…

◉ The SCSI chain includes internal SCSI devices that connect to the
SCSI host adapter and any external SCSI devices that connect to an
adapter’s external port.
◉ Multiple SCSI chains can exist in a system, and a computer can
contain up to four SCSI host adapters.
◉ A SCSI-1 host adapter supports up to seven internal or external
devices.
◉ SCSI-2 or higher adapters support up to 15 internal or external
devices.

266
 2.3.4 SCSI ID Configuration and Termination

◉ Each device on a SCSI chain, including the SCSI host adapter, is

assigned a SCSI ID. (Some SCSI hard drive manufacturers refer to
this setting as the drive select ID.)
◉ The SCSI ID allows each device to share the same SCSI bus, and it
assigns a priority for each device.
◉ The SCSI interface allows a SCSI device to communicate directly
with another SCSI device connected on the same SCSI chain.
◉ The higher the SCSI number, the higher the priority of the device on
the SCSI chain.
◉ SCSI IDs are normally set using switches, jumpers, SCSI BIOS
software, or manufacturer-provided software.
267
 Continued…

◉ Standard SCSI devices (8-bit devices) recognize SCSI IDs 0 through 7.

◉ Wide SCSI devices (16-bit devices) recognize SCSI IDs 0 through 15.

Figure 6.12 SCSI ID priority levels

◉ The SCSI host adapter is normally preset to SCSI ID 7, the highest

priority, and should not be changed.
◉ Slower devices such as scanners, CD/DVD drives, or video encoders
should be assigned a higher SCSI ID.
268
 Continued…

◉ 6 or 5 for a standard SCSI device and 15 or 14 for a Wide SCSI device,

so they receive ample time to move data onto the SCSI bus.
◉ SCSI ID 0 is the default for most SCSI hard drives.
◉ A development that is helpful in setting SCSI IDs is SCAM (SCSI
Configured AutoMatically).
◉ Termination of SCSI devices is very important.
◉ Proper termination of SCSI devices keeps the signals from bouncing
back up the cable and provides the proper electrical current level for
the SCSI chain.
◉ The SCSI bus cannot operate properly without terminating both ends
of the SCSI bus. 269
 Continued…

◉ SCSI termination is performed in several ways:

1. by installing a jumper;
2. by installing a terminator plug;
3. by setting a switch;
4. by installing a pass through terminator; or
5. with software.

270
 3. Removable Drive Storage

◉ IDE and SCSI are the two most common types of hard drives, but
these interfaces are also used for internal and external storage
devices such as CD/DVD drives and tape drives.
◉ IDE PATA has traditionally only been internal devices, but now with
SATA, external devices are available.
◉ SCSI has always supported internal and external devices.
◉ These external devices can also attach to the parallel port (not
common today) or the USB port (a very popular option).

271
 Continued…

◉ Tape drives can be attached using SCSI or IDE (SATA only) or attach
to parallel, USB, eSATA, or IEEE 1394 ports if they are external
devices.
◉ Tape drives are installed using similar methods of like devices that
use these ports.
◉ When tapes are used, the most common types of tapes used for
backups are DAT (digital audio tape) and Traven.
◉ The most common type of removable storage is optical (CD/DVD).

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 4. Troubleshooting storage devices

◉ Most problems with new drive installation stem from improper

configuration of jumpers, SCSI ID settings, termination, or problems
with cabling.
◉ The following steps assist with checking possible problems.
○ Check the physical settings, if necessary.
○ Check cabling.
○ Check drive type setting in BIOS Setup.
○ If after you have configured the drive, installed it, and powered it
on, the BIOS shows the drive type as “None, Not installed,” or
displays all 0s, then the BIOS is not able to detect it.
○ Has the drive been partitioned and one partition marked as the
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 Continued…

○ Has the drive been high-level formatted?

○ Verify that the mounting screw to hold the drive in the case is
not too tight.

NOTE: Stop 0x00000077 Kernel_Stack_Inpage error

If your computer has a boot sector virus or data cannot be read
from the paging file, run antivirus software for the potential virus. If
there is a paging file error, search for this error code on the Internet.
Depending on the output shown, take the appropriate steps.

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Figure 7.39 Hard drive mounting screws

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 Continued…

○ If during partitioning the “No fixed disks present” error appears,

check the hard drive cabling, power connection, configuration
jumpers (cable select, master/slave, SCSI ID), termination, and
BIOS configuration.
○ If the hard drive does not format to full capacity:
a) the drive parameters may be set incorrectly in Setup;
b) the BIOS does not support large hard drives; or
c) translation is not set up for the hard drive in the Setup
program. Confirm the drive’s parameters reported by the
Disk Management tool with the drive’s actual parameters
and capacity.

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 Continued…

○ If the error message “Disk Boot failure” appears, check to see

that the primary partition is marked active.
○ If during power-on the hard drive does not spin up or the hard
drive spins down after a few seconds, check the power
connector.
○ Run a virus checker on the system
○ Try a warm boot (ctrl + alt + del). If the drive is recognized after
the warm boot, the Setup program may be running too fast for
the drive to initialize.
○ Is the correct cable used?

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◉ The following are generic guidelines for hard drives that did work,
but are now having problems.
○ Run a virus-checking program after booting from a virus-free
boot disk. Many viruses are specifically designed to attack the
hard drive.
○ Has there been a recent cleaning of the computer or has
someone recently removed the top from the computer? If so,
check all cablings and configurations.
○ If the hard drive flashes quickly on boot up, the controller is
trying to read the partition table in the Master Boot Record. Use
the DISKPART command from recovery console to see if the
hard drive partition table is OK.
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 Continued…

○ Do you receive a message such as “Disk Boot Failure,” “Non-

System Disk,” or “Disk Error”? These errors may indicate a boot
record problem. The solution is to boot from a bootable disk or
CD to see if drive C: is available. The operating system may have
to be reloaded. Also, verify that the primary partition is marked
as active.
○ When Windows has startup problems due to incompatible
hardware or software, or a corrupted installation process, the
Advanced Options menu can help. This option can be selected
by pressing the F8 key during the boot process.
○ If an insufficient disk space error appears, delete unnecessary
files, including .tmp files. Empty the recycle bin.
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 Continued…

○ If the computer reports that the hard drive may have a defective
area, use the hard drive error checking tool (right-click) on the
hard drive volume, select Properties, select the Tools tab, and
click the Check now button.

○ A ticking sound is sometimes called by a failed or failing hard

drive.

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CHAPTER SEVEN
Bus and Cards

282
 List of contents

1. Bus: Types of Bus

2. Cards: Video Card, Sound Card, Network Card

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 1. Bus

◉ The motherboard bus is a set of wires that allows

one part of the motherboard to connect and
communicate with other parts of the motherboard,
including the central processing unit (CPU).
◉ It also serves as an interface between the CPU and
various external devices.
◉ All buses have a control bus, data bus, and power
bus.
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 Continued…

◉ The control bus is used by the CPU to send signals to

the different parts of the computer system to keep
the actions of the different parts coordinated.
◉ The data bus provides the path to transfer data and
instructions among the different components of the
computer.
◉ It is assisted by the address bus, which provides the
physical address of data in the system memory to
facilitate data transfers.
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 Continued…

◉ The power bus energizes the different components

of the computer system.
◉ Motherboard buses differ in terms of data bandwidth,
which refers to the amount of data expressed in bits
that the bus can transfer in a single pass.
◉ They also differ in clock speed, which is measured in
terms of megahertz (MHz) and tells how fast the bus
can transfer data.
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 Continued…

◉ Hardware engineers continuously develop new

buses with higher speeds to keep up with state-of-
the-art CPUs that work faster.
◉ Some buses become obsolete, while some others
get enhanced.
◉ It is therefore a must to carefully review the
specifications of the computer system and inspect it
thoroughly before deciding to buy it to make sure
that the computer is not yet technologically obsolete.
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 1.2 Types of Buses

◉ There are two types of motherboard buses

○ Internal buses: serves as the communication
highway of the motherboard. It links the different
parts of the computer to the CPU and the main
memory. Its primary task is to send data and
instructions to the different parts within the
motherboard, including the external bus.

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 Continued…

○ External buses: serves as the interface for

peripheral devices like hard disks, CD-ROM drives,
and flash drives to get connected to the CPU. The
shape of each interface is unique. This prevents
plugging a device to a wrong port, which could
cause damage to the device while being
connected to the CPU.

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 2. Expansion Cards

◉ An expansion card is an electronic card/board that is

used to add extra functionality to a computer.
◉ It is inserted into an expansion slot on the
motherboard of a computer.
◉ Expansion cards contain edge connectors that are
used to create an electronic link between
motherboard and card, thus enabling these two to
communicate.

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◉ Many different classes of expansion card are

available, including sound cards, video graphics
cards, network cards and so on.
◉ All expansion cards are used to enhance the quality
of their specific function.
○ For example, video graphics cards are used to
enhance the video quality on a computer.

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 2.1 Types of Cards

◉ A sound card:
○ It is an expansion component used in computers
to receive and send audio. Sound cards are
configured and utilized with the help of a software
application and a device driver. The input device
attached to receive audio data is usually a
microphone, while the device used to output
audio data is generally speakers or headphones.

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 Continued…

○ The sound card converts incoming digital audio

data into analog audio so that the speakers can
play it. In the reverse case, the sound card can
convert analog audio data from the microphone
into digital data that can be stored on the
computer and altered using audio software.
◉ Video card:
○ It is a PC component that is used to enhance the
quality of images showed on a display.
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 Continued…

○ It is attached to the motherboard and controls and

calculates an image's appearance on the screen.
The video card is an intermediate device that
accelerates the video throughput.
○ Videos cards are also known as graphics cards,
video adapters, display cards, graphic adapters
and graphic accelerators.

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◉ Network card:
○ A network card (also called a network adapter,
network interface card, or NIC for short) acts as
the interface between a computer and a network
cable. The purpose of the network card is to
prepare, send, and control data on the network.
○ To prepare data to be sent the network card uses
a transceiver, which transforms parallel data into
serial data.
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 Continued…

○ Each card has a unique address, called a MAC

address, assigned by the manufacturer, which lets
it be uniquely identified among all the network
cards in the world.
○ To ensure that the computer and network are
compatible, the card must be suitable for the
computer's data bus architecture, and have the
appropriate type of socket for the cable.

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