The document provides a comprehensive overview of various computer hardware components including keyboards, mice, motherboards, CPUs, and more. It highlights their functions, types, troubleshooting tips, and connections used in systems, touching on peripherals such as printers, scanners, and storage devices like HDDs and SSDs. Additionally, it outlines basic operational principles for components like BIOS, RAM, and graphics cards, along with their installation and maintenance instructions.

2. The keyboard is the basic input device . A keyboard is a
typewriter-style device, which uses an arrangement of
buttons or keys to produce some symbols requires pressing
and holding several keys simultaneously or in sequence .

3. Types of Key-
board
Standard
Keyboard
Laptop-size
Keyboard
Foldable
Keyboard
Projection
Keyboard
Software
Keyboard

4. • 5-pin DIN5 connector
(Deutsches Institute fur Normung
e.V../ Deustche Industrie Norm)
• 6-pin PS/2 connector
• 4-pin USB connector

5. A
Scan code
“1E” is
generated“
1E” is generated
Scan code
“1E” is
translated
into ASCII
code
number
65
We are
dealing
with an
“A”

6. • Keyboard is a largely a trouble-free device if handled
properly
• Do not spill liquids or food particles on the keyboard
– Computer may display keyboard error
– Keyboard is not working properly
• Computer may display keyboard errors.
• Keyboard is not working properly.

7. The PC mouse is a small device that allows user to
control and direct the on screen arrow or cursor using
one hand.

8. Types of
Mouse
Based on
Technology
Based on
Buttons
Based on
Interface
1. Mechanical
2. Opto -
mechanical
3. Optical
1. Single button
2. Double
button
3. Three button
4. Scroll button
1. Serial
2. Bus
3. Wireless
4. USB

9. • Serial Connector
• PS/2 Connector
• USB Connector

10. Mouse converts the movements to signals that the computer can
use.
• Mouse can give problems if not handled with care
• Do not spill liquid or other substances around the mouse
– Mechanical Mouse is not moving properly
– Cordless Mouse is not moving properly
– System does not recognize mouse
– Mouse does not move in a particular direction

11. A motherboard is a printed circuit board (PCB) which holds
many of the crucial components Of the system , such as the
central processing unit(CPU) and memory and provides
connector for other peripherals .

16. 1 . Instability in a New System .
2 . Motherboard has a Crack .
3 . System does not work properly after recent repair .
4 . System does not start though fans are working .
5 . When switched on, the system only beeps or shows
POST error .
6 . Intermittent crashing/stopping of system .
7 . System fails displaying Parity Error .

18. Types of
Ports
Serial Parallel DIN5 PS/2 Infrared Bluetooth USB Firewire

19. Serial
Parallel
DIN 5

20. PS/2 (DIN 6)
Infrared
Bluetooth

21. USB
Firewire

22. • USB connectors are used to connect
hardware device to System ,,.Like Printer,
Scanner, Pen drive, Mouse, Keyboard etc.
• PC may connect up to 127 USB devices at a
time, by using USB replicator.
Versions :
1) USB 1.0 (Original)
2) UBS 2.0 (High Speed)
3) USB 3.0 (Super Speed)

23.  CPU- Central Processing Unit.
The CPU is centrally located on the Motherboard
 The CPU carries out a large share of the work in
the computer.
CPU contains billions of transistors , placed on
silicon chip.
Generally home user computers use a single CPU.
Super , Mainframe computers uses multiple CPU
in parallel to handle the work load.

24.  Almost all computer system components are
connected to CPU either directly or indirectly .
 The CPU continually receives instructions to be
executed.
 The work itself consist mostly of calculations
& data transport.
 Other controlling related operations are also
done from CPU.

25. Steps to remove CPU
1. Open your cabinet system panel.
2. Remove power cable for CPU fan.
3. Carefully remove cooling fan which is mounted on CPU.
4. Finally very carefully open arrangement on CPU, and
then carefully remove the CPU.
5. Now you can fit new CPU on it , with same model no.
6. While attaching new one , first observe the notch on
CPU within in fraction of seconds.
7. Again fix the CPU fan , properly and plug the CPU fan
power cable again there from where you remove it.

26.  CMOS- Complementary Metal Oxide
Semiconductor.
 It is just a tiny battery , located on
Motherboard.
 CMOS used to
a) Saves BIOS settings
b) System date & time

27.  CR2032 for Desktop
 CR2016 for Laptop
 +3V
 Lithium
 Whenever system is started , firstly
BIOS setting are loaded from CMOS
battery . Basic device drivers also
load at boot time.

28.  Carefully remove battery, because careless
removing can damage CMOS battery lock ,
lock hold CMOS battery.
If CMOS fails then following error massages prompts
1) CMOS checksum error
2) System configuration lost
So, replace CMOS battery, with new CMOS battery.

29.  CD-ROM is an important media in the
PC world.
 CD-ROM is nothing but a component which
read and write the file into a removable Compact
Disk.

30. 1. IDE Connectors
2. Sata Connectors
CD-ROM Drive

31.  When any Compact Disk is inserted into it then as
user wants, read and write operations can be
performed.
– Ahead Nero – Enables to burn data from system to a CD
– Clone CD – Enables to create a duplicate copy of a CD
– AdenSoft Audio/Data Burner – Enables to create data backup on
the CD

32.  Check it on another PC if it doesn’t work , then
replace the CD-ROM.
 While removing CD - ROM from cabinet you
should have to remove screws, power
connector and Data connector.

33. DVD-ROM is nothing but a component which
read and write the file into a removable DVD.
Front Panel of DVD-ROM Drive
Connectors

34. • Memory :- Memory is the location where Data
can be hold during processing and save after
processing.
Types of Memory
Primary Memory :
Primary memory or Primary
Storage is the area where
data is stored for quick
access by computer
processer.
Secondary memory :
Secondary memory or
Secondary Storage is the
area where data can
stored permenantly.

35. Primary Memory
 RAM (Random
Access Memory)
 Rom (Read Only
Memory)
Secondary Memory
 Hard Disk
 Floppy Disk
 Compact Disk (CD)
 Digital Versatile Disk
(DVD)
 Pen Drive
 Micro Chip

36. • RAM stands for “ Random Access Memory.
• RAM is a computer’s temporary memory.
• It stores data or programs while they are being
used and requires power.
 Current Version :
1) DDR3 - Laptops & Desktops
2) DDR5 – Graphic related computers

37. • RAM is located next to the processor on the
motherboard.

38. SRAM : [Static RAM]
- Fast, has lower access time
-Typical access times 5-25ns.
- Expensive
- Cache memory is Static RAM
DRAM : [Dynamic RAM
- Slower, has higher access time
- Typical access times 60-120ns
- Much Cheaper than SRAM
- Main Memory is Dynamic
RAM

39.  Using BIOS Beep Codes
 Performs the POST test and ensures that the system is
working properly.
 After attaching insure that both side knob are packed
properly.
 While removing Carefully remove, by removing side knob
first.
 Remove RAM
 Check on another Working PC, if it not works then change
RAM.

40. •A hard disk is a primary and permanent data
storage device
•A hard disk consists of several circular platters
and each platter has read/write heads on both
the sides of it .
•HDD contains
1) Operating System
2) Softwares
3) Data

41. • ATA is a standard interface for connecting storage
devices such as hard disks and CD-ROM drives
• SATA is a high speed serial interface designed to
replace ATA and Ultra ATA drive interface standards.
• IDE port

43. Types
of HDD
Standard
Device
Serial
ATA
SCSI
HDD
External
HDD
Wireless
HDD

44. • Used to create multiple logical drives or
partitions
• Makes your system start faster and it also
enables you to install multiple operating
systems on the different partitions
• Fdisk utility enables you to divide the hard disk
into multiple partitions
• You can partition a hard disk
while installing operating system or
using a utility such as Fdisk or partition magic.

45.  Erases all the contents of the drive
 Creates the sectors, tracks and places the file system on the hard disk
 Format a hard disk after you install a new hard disk on the system or to
erase all the contents on the disk
 Two types:
1. Low Level Formatting
using Seagate Disk Manager S/W or in old BIOS
also called Physical format.
It create tracks
2. High Level Formatting
using Format command
also called Logical format
It convert track into sector

46. – System does not Start
– Hard Disk Drive contains bad sectors
– Hard Disk Drive crashes
– Hard Disk does not display the correct formatted
size
- Carefully remove connectors

47.  Also called Firmware
 The BIOS S/W enables you to control and
troubleshoot the system and the different
hardware components without loading the OS.
 The BIOS contains the code required to operate
the hardware devices connected to the system
such as the keyboard, mouse and the different
ports connected to the system

48.  DIP- Dual Inline Package- 32 pin
 PLCC- Plastic Leaded Chip Carrier- 28
pin

49. POST-Test microprocessor, RAM, chipset,
display card, disk drives & KB etc.
Setup- enables you to modify the settings
and store them in the CMOS e.g.
Changing boot sequence & to correct any
H/W problems such as enabling ports
that are disabled.
BIOS-collection of actual drivers which act
as basic interface between OS & H /W
when system is booting or running( date,
time etc).
Bootstrap Loader- reads HDD boot sector
to load OS . It is job of this program to
copy OS from drives to RAM
successfully.

50.  AMI- American Megatrends Inc.
 Award- now Merged in Phoenix
 Phoenix-
 MR BIOS- Microid Research

51. • Graphic Card is an extension card which generates a Feed of output
images to a display.
Types of Graphics
Card
On-Board PCI Express AGP External

52. PCI Express
Whenever CPU requires high Graphics performance,
then it is transferred to graphics Card.
1. Do not use roughly.
2. Away from earth surface.
3. Do not touch if connected.

If Card will damage then you should change that
because there is no chance of repairing.

53. • Accepts the Alternate Current (AC) current from the
power socket in the wall and converts the AC
current to the Direct Current (DC).
• Now a days power supplies are available in the
range of 250W to 400W

54. Power Connectors
Types of Power
Connectors
AT Power
Connectors
ATX Power
Connectors
Standard
peripheral
Connectors
Floppy Drive
Power
Connectors
2/3 Mini
Plug type
Connectors

55. • Cooling devices such as drive coolers and bay
coolers are used to cool down the system
components such as hard disk
Hard disk is placed in the
bay cooler that has fans for
cooling
drive coolers with the hard disk
drive, Has a fan that blows air
on the hard disk to cool it .

56. • System produces heat while it is functioning that
can damage the internal components of the
system.
1) Fans - System case and the system power supply
have a fan in it that helps channel air flow in or
out from the system case

57. • Various tools can be used to troubleshoot SMPS problem
• Due to a faulty power supply, the components of the system
may also get damaged
– System is not starting
– Power supply fan is not working
– Fuse is blown
– Power supply is dead
– SMPS voltage drops or increases
– Fan moves for a moment and then stops

58. • Is a short form for Modulator/Demodulator
• Modem is a communication device that
enables a computer to transfer data over the
telephone or cable lines
• Data transmission speed, data compression,
data or voice communication, fax capability
are the most common features of a modem

59. DTE DTE
Modem
DCE
Modem
DCE
Transmitted Data Received Data
Telephone line
Analog signal
Signal corrupted
by noise
Modem Protocols
Modem
protocols
Automatic
repeat request
(ARQ)
Link Access
Procedures for
Modems (LAPM)
Microcom
Network Protocol
(MNP)
K56Flex

60. Internal Modem :
A modem card that
you can plug into an
expansion slot on the
motherboard. It is
advisable to remove
the telephone line
when not used.
External Modem :
Connected to the PC
through a cable,
which is plugged into
serial port on the
back of the system
unit. (easy to install).

61. Read the modem documentation before
installing a modem
Wear an anti-static wristband
Ensure the computer is switched off and unplug
the power cord from the wall socket
Disconnect all the peripheral devices attached to
the computer

62. • To solve the problems that might arise due to
modem itself or due to communication
software such as auto dialer or dial up
connection.

63. • A printer is a peripheral output device that
prints images and text on paper.

64. • Impact Printers :
- image produce by
Hammering on a ink
ribbon
- Eg. Dot Matrix
• Non-Impact Printers:
- image produce by Ink
spraying.
- Heat process or
magnetization
- Eg. Inkjet , Laser
Inkjet Printer Laser Printer

65. • Standard Parallel Port (SPP)
• Enhanced Parallel Port (EPP)
• Enhanced Capabilities Port (ECP)

66.  Assemble the printer – Connect internal and
external parts of the printer
 Set up printer – Connect printer to the
appropriate port on computer
 Install Printer Drivers – Install printer driver
(software that controls operation of printer)
in the computer
 Configure the Printer – Set different settings
for the printer.

67. You may encounter following problems :
General Troubleshooting
Printer Driver is not functioning properly
Troubleshooting Dot Matrix Printers
Troubleshooting Inkjet Printers
Troubleshooting Laser Printers
 Turn OFF the printer before cleaning.
 Never spray cleaner on the printer itself.
 Use compressed air or a vacuum cleaner to remove dust.
 Do not place any electronics items near printer
 Don’t switch on and off the printer very frequently which
results into nozzles clogging.

68. • A scanner is a device that converts data on a
page to a format that can be stored on the
computer
• The image or document to be scanned must
be placed face down on the scanner glass
• Scanners have two or three mirrors in the
interior.

69. Types of
Scanners
Flatbed
Scanners
SheetFed
Scanners
Slide
Scanners
Drum
Scanners

70. 2) Heat sink - Heat sink is used to cool the
microprocessor and the other chips on the
system
1. Active – Removable
2. Passive – Fix to Processor

71. • A scanner can be connected through the :
1) Parallel
2) USB
3) SCSI port

72.  Scanner can be connected to parallel, SCSI or
USB port of a computer
 Read manual for instructions on settings for
the scanner and also to run a test scan.
 Many scanners come with additional
software.
 Read documentation that comes with
scanner and install any additional software if
it comes with your scanner.

73.  Computer does not recognize Scanner
 Computer does not start
 Scanner does not work
 Scanner does not work properly after a
system crash
 Cannot access USB scanner
 Scans are not clear

74.  Confirm power is on and scanner is also turned on
 If there is no power in scanner, swap power cable with another
one
 Try a test scan to ensure a problem is with installation or
configuration of computer
 Ensure document or image to be scanned is placed face down on
glass
 Wait till light stops blinking before lifting scanner lid.
 Check whether scanner is plugged in and power switch is on
 Shut down the computer and unplug it
 Check USB or SCSI port of scanner for proper connection
 Remove parallel port cable and inspect properly for any signs of
damage.