Computer hardware troubleshooting

Objectives :

1. Know the different beep codes and error codes.
2. Troubleshoot computer problems.
3. Preventive maintenance of a computer.

Basic Computer Troubleshooting Guide

1.Don't panic. Relax. Take a breath.
Many computer problems appear more serious than
they really are.

2.Make sure there really is a problem. Can't start your computer? Check the basics.
1.Examine the cables, connectors, and power cords to make sure they're plugged in
securely. Often times a loose cable or connector (power, network, keyboard, mouse, speaker,
monitor cable, etc.) is the cause of the problem.
2.If you're using a power strip or a surge protector, make sure it's on and that it works. Remember
that a surge protector may not be working because it is designed to self-destruct. When an
electric jolt is too much, your surge protector takes the hit saving your more expensive hardware
from the voltage.
3.Try plugging something else directly into the electrical outlet to make sure there isn't a power
problem.
4.Check to see if your monitor is on. Sounds silly, but it has solved my own problem more than
once.

3.Can’t get on to the network or the Internet?
1. Check to see if anyone else around you is having a similar problem. If so, there may be a
service outage affecting a wider area
2. Check to make sure the network cable is connected to both the computer and the wall or
modem.
3. Check where the network cable connection is made to the back of the computer, you should
see a little green light right where the cable connects. If the light isn’t on or flashing, then you
are not getting a signal to the computer. If rebooting doesn’t fix it, contact the Help Desk or
your ISP.

4.Error Messages - Write them down.
1.What tipped you off to the problem? Sometimes it's an error code or message displayed
on screen. Be sure to write it down — it may describe the problem and how serious it is.
Be sure to document the exact wording of any error messages. This can make the job of
the Help Desk much faster.
2.Other times you get no warning — everything just freezes. Message or no message, be
sure note what was going on when the problem occurred. Were you starting your
computer? Were you on the Windows Desktop? Were you in a particular application? Surfing
the Web?

5.Think about what changed recently on your computer.
Try to pinpoint when the trouble first started. Did the problem
coincide with any recent changes?
1.Did you change any settings? If you did you might want to change them back the way they
were.
2.Any peripherals been added or removed recently (such as a printer or external Memory Card
reader?)
3.Has anyone else been using your computer recently?
4.Have downloaded anything off the Web? File sharing and free MP3’s are an easy way to get a
virus on your machine.

6.The computer is on but…
1 Everything on the screen is frozen and the keyboard and mouse are not responding .
Try tapping on the Num Lock key. It’s located on the right-hand side of the keyboard above the
number 7. While tapping the Num Lock key, notice whether or not the Num Lock light goes on and
off. If it doesn’t, the computer is completely locked up. You’ll have to REBOOT the computer. If the
light does go off and on, wait a minute before giving up hope. It may come back to life on its own.

2 Pressing Alt + F4
If a software program stops working or freezes up, try pressing the ALT+F4 keys to close the window
that you’re currently working in. This can shut down a frozen window and bring the computer back
to life. If the keyboard is frozen as well, you’ll have to reboot.

3 The “Blue Screen” has appeared.

The dreaded “Blue Screen of Death”. There’s not a lot to be done except to reboot the machine. If it
keeps occurring, this is an indication of a major problem with the computer.

4 The computer is on, but there is no sound.
Is there a speaker icon next to the clock on the taskbar? (It’s in the lower right side of the screen) If you
can find it, double click the speaker icon to bring up the audio controls for the computer. See if any of
the volume controls have been muted or turned all the way down. Uncheck any Mute boxes that are
selected.

5 The computer is on, but the keyboard doesn’t
work
Swap the keyboard or try plugging the keyboard into another computer. If it doesn't work on the other computer, there is
likely something wrong with the keyboard. If it does work on the other computer, there is likely something wrong on the
computer or the connection to the computer.

6 CTRL-ALT-DEL
When you press the Ctrl-Alt-Delete buttons together, you will bring up a control panel where you can select “Task Manager”
and see if any of the programs are shown as “not responding”. You may be able to shut down the offending program from
there. If you can’t get to this screen, you’ll have to reboot.

7.Rebooting can do wonders.
Don’t just pull the plug!
A simple reboot may clear up the problem. Go to the Start Menu and select Shutdown. Didn't work? It's
time to try a forced reboot — with, unfortunately, no way to save your work — by pressing the
keysCTRL-ALT-DEL simultaneously twice in a row.
If that didn't work, you have no choice: you have to turn the computer off manually with the power
switch. Hold the power button down (for about 5 -10 seconds) and the computer will shut down. Wait
at least 10 seconds for the hard drive to stop spinning and then restart the machine.
If the computer starts up, start the applications you were using when the crash occurred. Some
programs, like Microsoft Word, make timed backups of your work and may bring up recovered files. If
the program notifies you that there is a “recovered document” save the file under a different name
and compare them to your previously saved files.

BEEP CODES
The beep pattern is telling you what part of the hardware is failing.
Unfortunately there are different standards for the beep pattern and you will
have to refer to your motherboard's user manual for the meaning of it. And
most common beep codes and error are as follows.

BEEP DESCRIPTION

1 Short Beep Normal POST, computer is ok.

Continuous Beep RAM Problem

One Long and Three Short Beeps. Indicates a video error has
occurred and the BIOS
cannot initialize the video
screen to display any
additional information

Troubleshooting Tips for New Monitors

Here are some basic trouble shooting tips for new monitors:

1. The picture does not appear

Check to make sure the signal cable is firmly connected in the socket.
Check to see if the computer system's power is ON.
Check that the Brightness Control is at the appropriate position, not
at the minimum.
2. The Screen is not synchronized

Check to make sure the signal cable is firmly connected in the socket.
Check that the output level matches the input level of your computer.
Make sure the signal timing of the computer system is within the
specification of the monitor.

3. The position of the screen is not in the center

Adjust the H-Size, H-Phase or V-Size, V-Center controls.
Check if the signal timing of the computer system is within the
4. The screen is too bright or too dark

Check if the Brightness or contrast control is at the appropriate position,
not at the maximum or minimum.
Check if the specified voltage is applied
Especially, check the horizontal frequency.
5. The screen is shaking

Move all objects that emit a magnetic field, such as a motor or transformer,
away from the monitor.
Check if the specified voltage is applied.

Troubleshooting Tips for a New Motherboard

More than 70% of all computer problems are related to cabling and connections. Ensure all
cables are connected and connected firmly. IDE and floppy ribbon cables and power cables can
often go loose. Ensure microprocessor, memory modules, and adapters such as video card are
inserted correctly and didn't "pop-up" due to vibration.

System has no power at all. Power light does not illuminate, fan inside the power supply
does not turn on, and indicator light on keyboard does not turn on.

PROBABLE CAUSE DIAGNOSIS SOLUTION

Power cable is Visually inspect power Make sure power cable is
unplugged. cable. securely plugged in.

Visual inspection, try
Defective power cable. Replace cable.
another cable.

Power cable and wall Contact technical
Power supply failure. socket are OK, but support
system is still dead.

Use different socket,
Faulty wall outlet;circuit Plug device into socket
repair outlet, reset circuit
breaker or fuse blown. know to work and test.
breaker or replace fuse.

System inoperative. Keyboard lights are on, power indicator lights are lit,
and hard drive is spinning.


Turn off computer. Take cover
Using even pressure on both
Expansion card is partially off system unit.
ends of the expansion card,
dislodged from expansion slot Check all expansion cards to
press down firmly on expansion
on the motherboard. ensure they are securely seated
card.
in slots.

Turn system off.
Disconnect the cables from
one of the floppy drives. Turn
Defective floppy disk drive or
on the system, check to see if Contact Technical Support.
tape drive.
the keyboard operates
normally. Repeat until you
have located defective unit.

Turn computer off. Make sure expansion card is
Defective expansion card.
Remove an expansion card. secure in expansion socket.

System does not boot from hard disk drive, can be booted from floppy
disk drive.


When attempting to run the Check cable running form disk to
FDISK utility described in the disk controller on the board. Make
Connector between hard drive HARD DISK section of the sure both ends are securely
and system board unplugged. manual you get a message, plugged in; check the drive type in
INVALID DRIVE the Standard CMOS Setup (in your
SPECIFICATION. motherboard manual).

Format hard disk; if unable to do
Damaged Hard Disk or Disk
so, the hard disk may be Contact Technical Support.
Controller.
defective.

Run the FDISK program, format Backing up the hard drive is
Hard Disk directory or FAT is the hard drive(See HARD DRIVE extremely important. All Hard
scrambled. section of manual). Copy your Disks are capable of breaking down
backup data back onto hard drive. at any time.

System only boots from Floppy Disk. Hard Disk can be read and applications
can be used, but booting from Hard Disk is impossible.

Error message reading "SECTOR NOT FOUND" or other error messages
indication certain data is not allowed to be retrieved.


Back up data and
applications files.
Reformat the Hard Drive
Hard Disk boot
A number of causes as described in the Hard
program has been
could be behind this. Drive section of the
destroyed.
manual. Re-install
applications and data
using backup disks.

Error message reading "SECTOR NOT FOUND" or other error messages
indication certain data is not allowed to be retrieved.


Back up any salvageable
data. Then do a low level
format, partition, and high
Use a file by file backup
level format of the hard
A number of causes could instead of an image
drive( see Hard Disk
be behind this. backup to backup the
section of your manual for
Hard Disk.
instructions). Re-install all
saved data when
completed.

Disk formatted on IBM PS/2 will not operate with this system.

Format disk in the AT type
The IBM PS/2 uses a IBM PS/2 disk format will
computer insert disk into the
different format than other not work in an AT type
IBM PS/2 and copy the files
computers. computer.
you wish.

After install an expansion card (network card, tape drive card, etc.) the
system no longer works properly.


Change the interrupt or RAM
address on the new expansion
All or part of the system may be card. See the documentation that
inoperable. The new card may came with the new card in order
No power to monitor.
work but a mouse or COM port to change pin settings. many
may not work. expansion devices come with
proprietary software that will
assist you in doing this.

Screen message says "Invalid Configuration" or "CMOS Failure.”

Incorrect information
Check the configuration Review system's equipment.
entered into the
program. Replace any Make sure correct
configuration (setup)
incorrect information. information is in setup.
program.

Screen is blank.
Check the power connectors
to monitor and to system.
Power connectors may be Make sure monitor is
No power to monitor.
loose or not plugged in. connected to display card,
change I/O address on
network card if applicable.
Monitor not connected to
See instructions above.
computer.
Network card I/O address
See instructions above.
conflict.

System does not boot from hard disk drive, can be booted from floppy disk
drive.

Check cable running form
When attempting to run the
disk to disk controller on the
FDISK utility described in
Connector between hard board. Make sure both ends
the HARD DISK section of
drive and system board are securely plugged in;
the manual you get a
unplugged. check the drive type in the
message, INVALID DRIVE
Standard CMOS Setup (in
SPECIFICATION.
your
Problem

Reboot computer. Re-install memory,
make sure that all memory modules are
Memory problem, display card installed in correct sockets. Check jumper
jumpers not set correctly. and switch settings on display card. See
display card section for information of
settings.

Use anti-virus programs (McAfee/PC-
Computer virus. cillin, E-port, etc) to detect and clean
viruses.

Screen goes blank periodically.
Screen saver is enabled. Disable screen saver.
Keyboard failure.
Reconnect keyboard.
Keyboard is Check keys again, if no
disconnected. improvement, replace
keyboard.

No color on screen.

If possible, connect
monitor to another
Faulty Monitor.
system. If no color,
replace monitor.
CMOS incorrectly set
Call technical support.
up.

Error reading drive A:

Bad floppy disk. Try new floppy disk.
Format floppy disk(type
Floppy disk not formatted
ENTER)

C: drive failure.
Boot from drive A: using
SETUP program does not DOS system disk. Input
have correct information. correct information to
SETUP program.
Hard Drive cable not
Check Hard drive cable.
connected properly.

Cannot boot system after installing second hard drive.

Master/Slave jumpers not Set master /Slave jumpers
set correctly. correctly.
Run SETUP program and
Hard Drives not select correct drive types.
compatible / different Call drive manufactures
manufacturers. for compatibility with
other drives.

Missing operating system on hard drive.
CMOS setup has been Run setup and select
changed. correct drive type.

Keyboard is locked, no keys function.
Keys jammed or
Replace keyboard.
defective.

Keyboard is locked, no keys function.

Keyboard is locked. Unlock keyboard

Video Cards & Display issues.

When loading, your computer
follows Is there a logo?

•Try disconnecting your monitors cable from your video
card!
If your monitor is working you should see a message
like "No Signal". It doesn't matter what is on the screen
as long as it shows something.
•Verify your cable. Are you missing pins from the head
of the cable?
•Reset all monitor Settings to default (contrast,
Brightness, color, ...)

Hard Drive Issues

Any problem that has anything to do with your HD can be diagnosed using the below
Flowchart. Remember to click on the questions to get more details about the question.

•The primary Master is a Hard Drive
as shown by the arrow, and the
secondary Master is a DVD Drive in
the picture above

•Do you see an error code, or a beep?

> If your Hard Drive was working and then
all the sudden it is not recognized (seen), by
your system then it is bad news. Try
changing the Hard Drive connection with
the CD ROM connection just to make sure it
is not the connection that is failing. If no
success, go to the Data Recovery page to see
if there is anything you can do to retrieve
your data

Computer working with minimum hardware ?
•Take out / unplug any non-essential component (CD ROM, PCI cards[except video],...) and try to boot.
•With the minimum components (CPU, 1 RAM, 1 video card[ if you have an on-board video card on your
motherboard, use that one], 1 Hard Drive) try swapping power cables and connector ribbons.
•Sometimes it is a connector or a slot that causes the problem. Trying different IDE ribbon cables or power wire
for the hard drives or checking the RAMs one by one on all the slots, can help in identifying damaged parts or
slots.
•Verify that the heatsink is in full contact with the CPU. CPUs not connected to heatsinks heat up in a matter of
seconds crashing, or turning the computer off.
•If this does not work, take the motherboard out of the casing. Sometimes there is a short between the
motherboard and the case. Put the motherboard on an insulated surface and try.
•You should have verified your power supply before getting to this page. If you have not, then proceed to power
supply test. If you have already done that, then we need to check your motherboard
•If you are not sure how to manipulate different parts click on the following links to get more informationon
how to install:

Computer hardware troubleshooting

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