Basic PC Troubleshooting Solving a problem requires first recognizing that there is one - which may be somewhat obvious - then logically and rationally determining where the problem could be, and narrowing thing down from there. Understand the task at hand. Understand how to accomplish those tasks. Determine whether there is really a problem. Identify the problem. Consider the activities, uses, and condition around the system. Correct the items found defective. Correct items that could cause a problem in the future The keys to solving these problems Knowing and understanding your system. Understanding enough about DOS or Windows to get the system booted up and run a program. Understanding how the software you use is supposed to work. Knowing what and where your components are. Knowing how to remove and insert the components and operate any switches or change their jumpers. Being able to recognize text, visual, and audible clues that indicate potential problem spots. Being familiar with your system’s documentation, and keeping tech. support number(s) for your system and software handy. Taking each aspect of the system and your work step-by-step and eliminating what does not fit the problem. Having patience and a will to do it. Having the proper hand tools to open and change parts in your system. Troubles and Errors Troubles and errors are classified into two categories: Fatal errors - are those errors that keep your computer from booting up. These can be caused by hardware failures or malfunction due to improper configuration of the hardware. On the hand Non-fatal errors – are errors are those errors that does not prevent your PC from booting up, but causes undesirable conditions, such as no sound coming from your speakers, or your printer is printing garbage or does not print at all. Common Errors Encountered By PC Users No display on screen No power, or Dead System Computer does not boot-up Keyboard does not work Jerky mouse pointer or mouse does not work No Sound coming from the speakers Computer hangs or crash Printer prints garbage or does not print at all POST – Power On Self Test The first thing that the BIOS does when it boots the PC is to perform what is called the Power-On Self-Test, or POST for short. The POST is a built-in diagnostic program that checks your hardware to ensure that everything is present and functioning properly, before the BIOS begins the actual boot. It later continues with additional tests (such as the memory test that you see printed on the screen) as the boot process is proceeding. What are tested by POST CPU Memory Video Card Hard Disk Drive(s) Floppy Disk Drive(s) Keyboard POST Error Messages Post error messages are classified into two: Audio error codes – composed of beeps generated by the BIOS, which indicates fault domains. Visual/Text error codes – are displayed on the screen to indicated fault domains. These are much easier to understand than audible error codes. Fatal Errors : sometimes referred to as B

1. Basic PC Troubleshooting
Basic PC Troubleshooting
A Starter’s Guide to PC Users
A Starter’s Guide to PC Users

2. The problem solving-process
The problem solving-process
Solving a problem requires first recognizing
that there is one - which may be somewhat
obvious - then logically and rationally
determining where the problem could be,
and narrowing thing down from there.

3. 1.
1. Understand the task at hand.
Understand the task at hand.
2.
2. Understand how to accomplish those
Understand how to accomplish those
tasks.
tasks.
3.
3. Determine whether there is really a
Determine whether there is really a
problem.
problem.
4.
4. Identify the problem.
Identify the problem.
5.
5. Consider the activities, uses, and
Consider the activities, uses, and
condition around the system.
condition around the system.
6.
6. Correct the items found defective.
Correct the items found defective.
7.
7. Correct items that could cause a
Correct items that could cause a
problem in the future
problem in the future

4. The keys to solving these
The keys to solving these
problems
problems
1.
1. Knowing and understanding your system.
Knowing and understanding your system.
2.
2. Understanding enough about DOS or
Understanding enough about DOS or
Windows to get the system booted up and
Windows to get the system booted up and
run a program.
run a program.
3.
3. Understanding how the software you use is
Understanding how the software you use is
supposed to work.
supposed to work.
4.
4. Knowing what and where your components
Knowing what and where your components
are.
are.
5.
5. Knowing how to remove and insert the
Knowing how to remove and insert the
components and operate any switches or
components and operate any switches or
change their jumpers.
change their jumpers.

5. 6.
6. Being able to recognize text, visual, and
Being able to recognize text, visual, and
audible clues that indicate potential
audible clues that indicate potential
problem spots.
problem spots.
7.
7. Being familiar with your system’s
Being familiar with your system’s
documentation, and keeping tech. support
documentation, and keeping tech. support
number(s) for your system and software
number(s) for your system and software
handy.
handy.
8.
8. Taking each aspect of the system and your
Taking each aspect of the system and your
work step-by-step and eliminating what
work step-by-step and eliminating what
does not fit the problem.
does not fit the problem.
9.
9. Having patience and a will to do it.
Having patience and a will to do it.
10.
10. Having the proper hand tools to open and
Having the proper hand tools to open and
change parts in your system.
change parts in your system.

6. Troubles and Errors
Troubles and Errors
Troubles and errors are classified into two categories:
Troubles and errors are classified into two categories:
• Fatal errors
Fatal errors - are those errors that keep your computer from
- are those errors that keep your computer from
booting up. These can be caused by hardware failures or
booting up. These can be caused by hardware failures or
malfunction due to improper configuration of the hardware. On
malfunction due to improper configuration of the hardware. On
the hand
the hand
• Non-fatal errors
Non-fatal errors –
– are errors are those errors that does not
are errors are those errors that does not
prevent your PC from booting up, but causes undesirable
prevent your PC from booting up, but causes undesirable
conditions, such as no sound coming from your speakers, or
conditions, such as no sound coming from your speakers, or
your printer is printing garbage or does not print at all.
your printer is printing garbage or does not print at all.

7. Common Errors Encountered By
Common Errors Encountered By
PC Users
PC Users
 No display on screen
No display on screen
 No power, or Dead System
No power, or Dead System
 Computer does not boot-up
Computer does not boot-up
 Keyboard does not work
Keyboard does not work
 Jerky mouse pointer or mouse does not work
Jerky mouse pointer or mouse does not work
 No Sound coming from the speakers
No Sound coming from the speakers
 Computer hangs or crash
Computer hangs or crash
 Printer prints garbage or does not print at all
Printer prints garbage or does not print at all

8. POST – Power On Self Test
POST – Power On Self Test
 The first thing that the BIOS does when it boots
The first thing that the BIOS does when it boots
the PC is to perform what is called the
the PC is to perform what is called the Power-On
Power-On
Self-Test
Self-Test, or
, or POST
POST for short. The POST is a built-in
for short. The POST is a built-in
diagnostic program that checks your hardware
diagnostic program that checks your hardware
to ensure that everything is present and
to ensure that everything is present and
functioning properly, before the BIOS begins the
functioning properly, before the BIOS begins the
actual boot. It later continues with additional
actual boot. It later continues with additional
tests (such as the memory test that you see
tests (such as the memory test that you see
printed on the screen) as the boot process is
printed on the screen) as the boot process is
proceeding.
proceeding.

9.  CPU
CPU
 Memory
Memory
 Video Card
Video Card
 Hard Disk Drive(s)
Hard Disk Drive(s)
 Floppy Disk Drive(s)
Floppy Disk Drive(s)
 Keyboard
Keyboard
What are tested by POST
What are tested by POST

10. POST Error Messages
POST Error Messages
Post error messages are classified into two:
Post error messages are classified into two:
 Audio error codes
Audio error codes – composed of beeps
– composed of beeps
generated by the BIOS, which indicates
generated by the BIOS, which indicates
fault domains.
fault domains.
 Visual/Text error codes
Visual/Text error codes – are displayed
– are displayed
on the screen to indicated fault domains.
on the screen to indicated fault domains.
These are much easier to understand
These are much easier to understand
than audible error codes.
than audible error codes.

11. Fatal Errors :
Fatal Errors : sometimes referred to as
sometimes referred to as Boot-Up
Boot-Up or
or Start-
Start-
Up Errors
Up Errors
 Dead System
 No Display
 Hard Disk Failure
 CD-ROM failures
 Floppy Disk failures
 Memory failures

12. Dead System
Dead System
Symptoms:
Symptoms:
 No display on the screen
No display on the screen
 No lights on the front panel of the system
No lights on the front panel of the system
 No audible beep codes
No audible beep codes
 Power supply fan does not spin
Power supply fan does not spin
Fault Domains
Fault Domains
 No Power on the wall outlet or Power cord not plugged-in on
No Power on the wall outlet or Power cord not plugged-in on
the wall outlet
the wall outlet
 AVR/UPS not turned ON
AVR/UPS not turned ON
 Defective power cord
Defective power cord
 System’s power button not turned ON
System’s power button not turned ON
 Defective system power supply
Defective system power supply
 Defective AVR/UPS
Defective AVR/UPS
 Defective Motherboard
Defective Motherboard

13. Dead System
Dead System
Solutions:
Solutions:
 Check power source.
Check power source.
 Check / Replace power cord
Check / Replace power cord
 Check / Replace AVR/UPS
Check / Replace AVR/UPS
 Turn ON the system’s power switch
Turn ON the system’s power switch
 Check / Replace system’s power supply unit
Check / Replace system’s power supply unit

14. No Display / Video Adapter
No Display / Video Adapter
Failure
Failure
Symptoms: (one or more of the ff.)
Symptoms: (one or more of the ff.)
 No display on the screen
No display on the screen
 No Beep(s)
No Beep(s)
 1 Beep
1 Beep
 1 long 3 short beeps*
1 long 3 short beeps*
 Repeating long beeps*
Repeating long beeps*
 Orange or blinking LED on the monitor
Orange or blinking LED on the monitor
Fault Domains
Fault Domains
 Monitor is OFF
Monitor is OFF
 Defective motherboard or CPU
Defective motherboard or CPU
 Defective power supply unit
Defective power supply unit
 No RAM installed
No RAM installed
 Monitor’s contrast/brightness setting is set too low
Monitor’s contrast/brightness setting is set too low
 Defective video card
Defective video card
 Monitor is not connected to video card
Monitor is not connected to video card
*Depends on the BIOS manufacturer

15. No Display
No Display
Solutions:
Solutions:
 Turn ON your monitor.
Turn ON your monitor.
 Check the Contrast/Brightness setting on your monitor
Check the Contrast/Brightness setting on your monitor
 Check connections from monitor to video card
Check connections from monitor to video card
 Check / Replace Video card
Check / Replace Video card
 Check / replace RAM modules
Check / replace RAM modules
 Check / replace motherboard or CPU
Check / replace motherboard or CPU

16. Hard Disk Failures
Hard Disk Failures
Symptoms: (one or more of the ff.)
Symptoms: (one or more of the ff.)
 “
“Primary / Secondary /Master /Slave hard disk fail” is
Primary / Secondary /Master /Slave hard disk fail” is
displayed on the screen during boot-up
displayed on the screen during boot-up
 “
“Disk Boot failure. Insert System Disk” is displayed on the
Disk Boot failure. Insert System Disk” is displayed on the
screen during boot-up
screen during boot-up
 “
“Non-system disk” is displayed on the screen during boot-up
Non-system disk” is displayed on the screen during boot-up
Fault Domains
Fault Domains
 No hard disk drive installed on the system
No hard disk drive installed on the system
 No O.S. on the installed Hard disk
No O.S. on the installed Hard disk
 Defective hard disk drive
Defective hard disk drive
 Wrong jumper settings on the HDD
Wrong jumper settings on the HDD
 BIOS did not recognize the installed HDD
BIOS did not recognize the installed HDD
 Wrong configuration on the BIOS/CMOS setup
Wrong configuration on the BIOS/CMOS setup
 Defective IDE cable on the Hard Disk Drive
Defective IDE cable on the Hard Disk Drive
 Power supply not connected to the HDD
Power supply not connected to the HDD

17. Hard Disk Failures
Hard Disk Failures
Solutions:
Solutions:
 Install a Hard Disk Drive on the system
Install a Hard Disk Drive on the system
 Install an OS on the System or format the drive with “/s”
Install an OS on the System or format the drive with “/s”
option
option
 Check the settings or reconfigure the system on the
Check the settings or reconfigure the system on the
BIOS/CMOS setup
BIOS/CMOS setup
 Check / correct the jumper settings on the Drives
Check / correct the jumper settings on the Drives
 Check / replace HDD
Check / replace HDD
 Check / replace IDE cable on the Hard Disk Drive
Check / replace IDE cable on the Hard Disk Drive
 Check the power supply connector to the HDD
Check the power supply connector to the HDD

18. CD-ROM failures
CD-ROM failures
Symptoms: (one or more of the ff.)
Symptoms: (one or more of the ff.)
 See items at “Hard Disk Failure”
See items at “Hard Disk Failure”
 Cannot boot from CD-ROM
Cannot boot from CD-ROM
 Cannot read data from CD-ROM
Cannot read data from CD-ROM
 Cannot access the CD-ROM drive in DOS mode.
Cannot access the CD-ROM drive in DOS mode.
 CD-ROM tray wont eject
CD-ROM tray wont eject
 CD-ROM was detected during boot-up but missing in My Computer
CD-ROM was detected during boot-up but missing in My Computer
Fault Domains
Fault Domains
 BIOS does not support boot from CD-ROM
BIOS does not support boot from CD-ROM
 CD-ROM Disk is non-bootable
CD-ROM Disk is non-bootable
 Unrecognized CD-ROM Format.
Unrecognized CD-ROM Format.
 BIOS did not detect or recognize the drive
BIOS did not detect or recognize the drive
 Power or IDE cables not connected or improperly seated.
Power or IDE cables not connected or improperly seated.
 Device drivers were not installed
Device drivers were not installed
 Boot Sector virus disabled the IDE controllers
Boot Sector virus disabled the IDE controllers

19. Solutions:
Solutions:
 Update motherboard BIOS to support boot from CD-ROM
Update motherboard BIOS to support boot from CD-ROM
 Use a bootable CD-ROM disk. (original OS installer disk
Use a bootable CD-ROM disk. (original OS installer disk
preferred)
preferred)
 Check settings on the BIOS/CMOS for the “Boot Sequence”
Check settings on the BIOS/CMOS for the “Boot Sequence”
 Check / Correct the jumper settings on the Drives
Check / Correct the jumper settings on the Drives
 Check / replace CD-ROM drive
Check / replace CD-ROM drive
 Check / replace IDE cable on the Hard Disk and CD-ROM
Check / replace IDE cable on the Hard Disk and CD-ROM
drive.
drive.
 Check power supply to the CD-ROM
Check power supply to the CD-ROM
 Run Anti-Virus Program to check the system
Run Anti-Virus Program to check the system
CD-ROM failures
CD-ROM failures

20. Floppy Disk Drive Failure
Floppy Disk Drive Failure
Symptoms: (one or more of the ff.)
Symptoms: (one or more of the ff.)
 “
“Floppy disk fail (XX)” is displayed on the screen during boot-up
Floppy disk fail (XX)” is displayed on the screen during boot-up
 Steady LED lamp on the Floppy Disk drive
Steady LED lamp on the Floppy Disk drive
 Cannot read or write data onto a floppy diskette
Cannot read or write data onto a floppy diskette
 Floppy disk drive runs without user intervention and even without a
Floppy disk drive runs without user intervention and even without a
diskette on the drive.
diskette on the drive.
Fault Domains
Fault Domains
 Defective Floppy Disk drive
Defective Floppy Disk drive
 Defective FDD controller cable
Defective FDD controller cable
 Reverse connection of FDD controller cable
Reverse connection of FDD controller cable
 Wrong configuration on the BIOS/CMOS setup
Wrong configuration on the BIOS/CMOS setup
 Power supply is not connected to the FDD
Power supply is not connected to the FDD
 Defective diskette
Defective diskette
 Dirty Floppy Disk Drive’s read/write head
Dirty Floppy Disk Drive’s read/write head
 Virus/Trojan/Worm has infected the system
Virus/Trojan/Worm has infected the system

21. Floppy Disk Drive Failure
Floppy Disk Drive Failure
Solutions:
Solutions:
 Check / replace FD drive
Check / replace FD drive
 Check / replace FD controller cable
Check / replace FD controller cable
 Check power supply
Check power supply
 Replace defective diskettes
Replace defective diskettes
 Clean FDD’s read/write head
Clean FDD’s read/write head
 Install antivirus software and scan the system
Install antivirus software and scan the system

22. Memory Errors
Memory Errors
Symptoms: (one or more of the ff.)
Symptoms: (one or more of the ff.)
 Repeating Long Beeps*
Repeating Long Beeps*
 “
“Memory Test Fail” is displayed on the screen during boot-up
Memory Test Fail” is displayed on the screen during boot-up
 Restarts the PC every time Windows
Restarts the PC every time Windows®
®
starts-up
starts-up
 Frequent BSODs (blue screen of death)
Frequent BSODs (blue screen of death)
 System hangs-up or crash
System hangs-up or crash
 Corrupted Windows
Corrupted Windows®
®
registry
registry
Fault Domains:
Fault Domains:
 No RAM Module is installed on the system
No RAM Module is installed on the system
 RAM Module(s) is/are not seated properly on its slots
RAM Module(s) is/are not seated properly on its slots
 Defective RAM modules
Defective RAM modules
 Incompatible RAM modules installed on the system
Incompatible RAM modules installed on the system

23. Solutions:
Solutions:
 Install the same type of memory modules. (same brand and
Install the same type of memory modules. (same brand and
speeds preferred)
speeds preferred)
 Check / Replace RAM modules
Check / Replace RAM modules
Memory Errors
Memory Errors

24. Non-fatal Errors
Non-fatal Errors
 No Sound coming from speakers
No Sound coming from speakers
 Poor Display Quality
Poor Display Quality
 Jerky Mouse movement or does not
Jerky Mouse movement or does not
work at all.
work at all.
 System Hangs or crashes
System Hangs or crashes

25. No Sound coming from the speakers
No Sound coming from the speakers
Fault domain:
Fault domain:
 Speakers are not connected to sound card
Speakers are not connected to sound card
 Speakers are not turned ON
Speakers are not turned ON
 Speakers are connected on the wrong jack
Speakers are connected on the wrong jack
 Volume control’s setting is too low
Volume control’s setting is too low
 Defective speakers
Defective speakers
 No sound card installed on the system
No sound card installed on the system
 Sound card drivers are not installed
Sound card drivers are not installed
 Defective sound card
Defective sound card
Solutions:
Solutions:
 Connect the speaker to the sound card and on the proper jack.
Connect the speaker to the sound card and on the proper jack.
 Check speaker’s volume setting and Windows
Check speaker’s volume setting and Windows®
®
system mixer.
system mixer.
 Install the software/device driver of the sound card.
Install the software/device driver of the sound card.
 Check / Replace the speakers.
Check / Replace the speakers.

26. Keyboard errors
Keyboard errors
Symptom(s):
Symptom(s):
 “
“Keyboard error or keyboard not connected” is displayed on
Keyboard error or keyboard not connected” is displayed on
the screen during boot-up
the screen during boot-up
 No character appears on the screen when key is pressed
No character appears on the screen when key is pressed
 The LED indicator on the keyboard are steady or does not lit
The LED indicator on the keyboard are steady or does not lit
Fault domain:
Fault domain:
 Keyboard is defective or not connected
Keyboard is defective or not connected
 Keyboard is connected on the mouse port when both have
Keyboard is connected on the mouse port when both have
PS/2 connector
PS/2 connector
Solution(s ):
Solution(s ):
 Check / replace keyboard
Check / replace keyboard
 Install the keyboard on the correct port
Install the keyboard on the correct port

27. Mouse Errors
Mouse Errors
Symptom(s):
Symptom(s):
 Jerky movement of the mouse pointer
Jerky movement of the mouse pointer
 Mouse pointer moves vertical or horizontal direction only or does not
Mouse pointer moves vertical or horizontal direction only or does not
move at all
move at all
Fault domain:
Fault domain:
 Dirty mouse rollers and ball.
Dirty mouse rollers and ball.
 Defective mouse cable.
Defective mouse cable.
 Mouse is not connected to the system.
Mouse is not connected to the system.
 Mouse is not installed on the correct port (interchanged w/ the
Mouse is not installed on the correct port (interchanged w/ the
keyboard)
keyboard)
 Mouse device drivers are not installed.
Mouse device drivers are not installed.
Solutions :
Solutions :
 Clean your mouse’s rollers and ball
Clean your mouse’s rollers and ball
 Check / replace mouse
Check / replace mouse
 Install the mouse on the correct port
Install the mouse on the correct port
 Install the mouse’s device driver
Install the mouse’s device driver

28. Display errors
Display errors
Symptom(s):
Symptom(s):
 Has display on the screen at start-up but disappears before
Has display on the screen at start-up but disappears before
the Windows
the Windows®
®
desktop loads.
desktop loads.
 Poor image detail
Poor image detail
Fault domain:
Fault domain:
 Incorrect Desktop resolution setting.
Incorrect Desktop resolution setting.
 Incompatible Video card and monitor.
Incompatible Video card and monitor.
 Device drivers for the video card are not installed.
Device drivers for the video card are not installed.
 Outdated video card drivers.
Outdated video card drivers.
Solutions :
Solutions :
 Start in Safe mode(Win9x/Me) or VGA mode(Win2k/XP) then
Start in Safe mode(Win9x/Me) or VGA mode(Win2k/XP) then
set the display to the appropriate display setting.
set the display to the appropriate display setting.
 Install/Update the device drivers of the video card.
Install/Update the device drivers of the video card.

29. System hangs or crash
System hangs or crash
Symptom(s):
Symptom(s):
 System hangs or crashes frequently
System hangs or crashes frequently
 BSOD (blue screen of death)
BSOD (blue screen of death)
Fault domain:
Fault domain:
 See Memory Errors
 Insufficient amount of RAM installed in the system
Insufficient amount of RAM installed in the system
 Too many running programs
Too many running programs
Solutions :
Solutions :
 See Memory Errors
 Install / Add More RAM in the system
Install / Add More RAM in the system
 Avoid running to many programs simultaneously
Avoid running to many programs simultaneously