PC
Hardware Troubleshooting Techniques
Here you will learn about
computer hardware troubleshooting techniques,
cable testers, software diagnostic routines,
POST cards, error diagnostic methods.
Computer hardware is the physical part
of a computer and it is frequently changed
as compared to the software. Most computer
hardware is inside the computer and
cannot be seen by normal users. There
are a large number of the computer hardware
devices including Hard disk, CD-Rom,
RAM, Motherboard, Monitor, printer,
peripheral devices and other devices.
One of the first steps in the troubleshooting
is to sort out the hardware and software
problems. You can use the event viewer
utility in the Windows operating systems
to identify the nature and cause of
the hardware or software problem. Also
you can identify the hardware problems
by identifying the initial start up
beeps.
Errors that occur before
the initial beep shows that there is
some kind of hardware problem exists
in the system. At the POST stage, only
the BIOS of the system and basic hardware
is active and operating system does
not starts to initialize at this stage
until a final beep occurs. If a computer
produces an error (“The system
has detected Unstable RAM”) or
a beep code appears, this means that
system and found a problem with the
devices and system RAM should be changed.
Additionally, if the system starts up
process reaches the point where CMOS
configuration information is displayed
on the screen this means that there
is no problem detected with the basic
hardware of the system. After this point,
the system starts to load the device
drivers and operating system.
You can categorize the
system configurations errors and components
failure errors. Sometimes configurations
or setup problems occur when a new hardware
is installed and used in the system
for the first time. These problems occur
due to the mismatches of the CMOS memory
information and component's configuration
information. It is usually advisable
to access the system CMOS when the system
is first time prepared, when it is necessary
to replace the CMOS battery and when
a new device such as hard disk, CD-Rom,
RAM, Video adapter etc added to the
system. In most of the computers, the
BIOS use plug and play techniques to
detect most of the devices. These components
provide system resources to the newly
added device. When you are installing
a new devices or software, you may notice
some configuration errors.
If you face the configuration
errors, you should see the installation
manual that comes with the new computer
device. If you cannot confirm configuration
problems and the device is not working
properly, this means that there must
be some defect in the hardware. The
symptoms and errors can be divided into
the three parts such as boot up problems,
configurations problems and operational
problems. First of all system’s
configurations settings are checked.
The error messages that occur during
or after the end of the POST are reported
so it is important to observe that where
the problem is actually occurred.
Configuration
Error Messages Meanings
Press F1 to continue
Invalid configuration
CMOS time and date not set CMOS battery
error
CMOS memory size mismatches System configuration
and setup failure
CMOS system option not set CMOS battery
failure or CMOS checksum
After the beep tones
occur during the startup process, the
system now looks and loads the operating
system. The errors that occur between
the beeps and initializing the operating
system can be categorized into the following
categories.
• Hardware failure
( due to the physical problem with the
booting drive)
• General Failure Error Reading
Drive x
• Bad or Missing Command Interpreter
• Non system Disk or Disk Error
• Bad File Allocation Table
• Corrupted or missing operating
system files
• Corrupted or missing boot files
The configuration or
boot up problems can be occurred to
the hardware or operational function’s
failure and if the configuration is
correct and these error appears this
means there is some problems in the
hardware and boot up problems are normally
linked with the operating system.
PC Hardware
Troubleshooting Tools
Due to the low cost of
the some of the hardware components,
it’s usually not advisable to
repair the IC level problems of the
components, instead they should be replaced.
The repair cost of the component will
most likely be high as compared to the
actual cost of the component. There
are some very excellent hardware problem
detection tools that are very helpful
in identifying and isolating the problems.
These tools included Multi meter, Cable
Tester, POST card and software diagnostic
disk.
Software Diagnostics
Routines
Many disk based diagnostic
methods can check the system and identify
the problems by running the number of
tests on the different areas of the
system hardware. These tests produce
the visual reports and error messages
to identify the nature of the problem.
The most common software troubleshooting
routines check the computer’s
memory, keyboard, monitor, system processor,
and hard disk’s speed. If the
system CPU, hard disk and system clock
is working properly, then you will be
able to localize the problem by targeting
the other points in the system. If the
diagnostic tools/routines identify a
number of defective software/hardware
then you should replace one defective
unit a time.
Troubleshooting
with Multimeter
Testing tools can help
in isolating the hardware or software
problems and digital multimeter is a
most important tool for the electronic
troubleshooting. Digital Multimeter
and other electronic test instruments
are available in analog and digital
form and these instruments can be used
to measure the electrical values of
the voltage, current in miliamperes
and resistance in ohms. These devices
are known as Volt-ohm-milimeters (VOMs)
for the analog signals and digital millimeters
(DMMs) for the digital types. You can
also check the transistors, capacitors,
motor windings and diodes with the digital
multimeter. In computer troubleshooting,
most of the tests of the digital multimeter
are to check the DC readings.
Troubleshooting
with Cable Testers
The most common hardware
related compute networking problem is
the bad cabling and RJ-45 connectors.
There are a number of devices, designed
for testing the network communication
cabling. These devices include continuity
tester, time domain reflectometer and
cabling testers. Data cabling testers
are designed to perform a number of
different types of tests on the UTP/STP
and coaxial cables. The master end of
the cable tester is attached to one
end of the cable and the load unit of
the cable tester is attached to the
other end of the cable. The master unit
sends the signals through the cable
and reads them from the load unit. When
testing the cables, these devices normally
detect the problems such as crossed-over
wiring, broken wires, short connections
and the cable connections that are improperly
impaired.
Troubleshooting
with POST Cards
A POST card is a diagnostic
and troubleshooting device that is plugged
into the expansion slots and tests the
operation of the system as it boots
up. These cards can be as direct memory
access or they can be complex as ROM
BIOS diagnostic tools that perform the
advance level diagnostic tests. POST
cards are generally used when the computer
systems appear to be dead or the system
is unable to read from the floppy or
hard disk. The POST routines generally
report two types of errors fatal and
non fatal.
The fatal error stops
and system and when the POST card observes
non fatal errors, they should be read
very carefully because the error code,
which is indicated must be coordinated
with the timing of the error message
or beep code produced by the BIOS routines.
Normally POST cards come with the LEDs
(light-emitting diodes that produces
code error signals and they identify
any kind of problem.