Hardware Reference
In-Depth Information
Chapter 20. PC Diagnostics, Testing, and Maintenance
PC Diagnostics
NomatterhowwellbuiltyourPCisandhowwellwrittenitssoftware,problemscanoccur.
Diagnostic software can help troubleshoot problems when your computer malfunctions or
you are in the process of upgrading a system component, or especially when you are build-
ing an entirely new system from scratch. This chapter examines several types of diagnostic
software,including thebuilt-in POST(power-onselftest)aswellascommercial andopen-
source diagnostic software.
You also might find that your system problems are caused by a hardware malfunction and
that you must open the computer case to perform repairs. This chapter examines the tools
and testers used to upgrade and repair PCs—both the basic items every user should own
and some of the more advanced devices.
Of course, the best way to deal with a problem is to prevent it from occurring in the first
place. The preventive maintenance sections of this chapter describe the procedures you
should perform on a regular basis to keep your system in good working order.
Diagnostics Software
Several types of diagnostic software are available for PCs. Some diagnostic functions are
integrated into the PC hardware directly, whereas others take the form of operating system
utilities or separate software products. This software, some of which is included with the
system when purchased, can assist users in identifying many problems with a computer's
components. The types of diagnostic software are as follows:
•
POST
—ThistestrunswheneveraPCisturnedon.Theseroutinesarecontainedwithin
the motherboard ROM as well as ROMs on expansion cards.
•
Manufacturer-supplied diagnostics software
—Many of the larger manufactur-
ers—especially high-end, name-brand manufacturers such as HP/Compaq, Dell, Len-
ovo, and others—offer or include special diagnostics software expressly designed for
their systems. In most cases, these utilities are included with the system, or you can
download them from the manufacturer's website at no charge. Some manufacturers
write their own diagnostics, but most purchase the rights to an existing commercial
package that is subsequently customized or privately labeled. In some systems, the dia-
gnostic software isinstalled onaspecial partition ontheharddriveandcanbeaccessed
during startup. This is a convenient way for manufacturers to ensure that users always
have diagnostics available.
