Hardware Reference
In-Depth Information
display, and turn up the brightness and contrast controls to at least two-thirds of the maximum. If
you can't get any video display but the system seems to be working, try moving the card to a
different slot (if possible) or try a different video card or monitor.
4.
To enable the system to boot from a hard disk, make sure no floppy or optical discs are in any
of the drives. Alternatively, put a known-good bootable floppy or optical disc with diagnostics
on it in a drive, or attach a bootable USB drive for testing.
5.
Turn on the system. Observe the power supply, chassis fans (if any), and lights on either the
system front panel or power supply. If the fans don't spin and the lights don't light, the power
supply or motherboard might be defective.
6.
Observe the power-on self test (POST). If no errors are detected, the system beeps once (if the
computer has a speaker in the case) and boots up. Errors that display onscreen (nonfatal errors)
and that do not lock up the system display a text message that varies according to BIOS type and
version. Record any errors that occur and refer to the POST error codes earlier in this chapter
for more information on any specific codes you see. Errors that lock up the system (fatal errors)
are indicated by a series of audible beeps on systems that have a built-in speaker.
7.
Confirm that the operating system loads successfully.
Problems During the POST
Problems that occur during the POST are usually caused by incorrect hardware configuration or
installation. Actual hardware failure is a far less-frequent cause. If you have a POST error, check the
following:
• Are all cables correctly connected and secured?
• Are the configuration settings correct in Setup for the devices you have installed? In particular,
ensure the processor, memory, and hard drive settings are correct.
• Try clearing the CMOS RAM completely (most motherboards have a jumper for this), and then
run the BIOS Setup and check the settings.
• Are switches and jumpers on the motherboard properly set, especially if changed from the
default settings?
• Is the power supply set to the proper input voltage (110V-120V or 220V-240V)?
• Is the power supply defective? Try replacing it with a known-good spare.
• Are adapter boards and disk drives installed correctly? Try reseating or reconnecting them.
• Is a keyboard and mouse attached? Try replacing them with known-good spares.
• Is a bootable hard disk (properly partitioned and formatted) installed? Try disconnecting it and
booting from a floppy, optical disc, or USB flash drive instead.
• Does the BIOS support the hard disk drive you have installed, and if so, are the parameters
entered correctly?
• Are all memory modules installed correctly? Try reseating them.
Problems Running Software
Problems running application software (especially new software) are usually caused by or related to
the software itself or are due to the fact that the software is incompatible with the system. Here is a
list of items to check in that case:
