Chapter 7: Computer Memory^151
good. These specially designed devices can also test for any indication that the memory
may fail in the future. A SIMM/DIMM tester is fairly expensive and may be beyond the
practical needs of the average users. However, if you support, maintain, or repair a large
group of PCs on a regular basis, it would be a good idea to have one on hand.Installing Memory Modules in a PC
Before you open the system case and begin installing new memory modules in your PC,
regardless of whether you are replacing existing modules or inserting additional memory,
there are a few precautions you should take: Back up the system Anytime you open the system case to add, remove, or
replace components such as the processor, memory, the power supply, or a
disk drive, you should create a backup of the hard disk drive, especially if you
are working on the hard disk drive itself. You never know what can happen,
and it’s better to be safe than to lose everything on the hard disk. If you have a
large hard disk, you should use a tape drive, writable CD-ROM, back up across
a network (perhaps the Internet), or use lots and lots of diskettes.
Protect against ESD Always protect the PC against ESD (electrostatic discharge),
the static electricity that can build up in the PC and you. It doesn’t take much
in the way of an ESD charge to damage a memory module. Work in an antistatic
environment and wear an antistatic wrist or ankle strap.
Work in a well-lighted area Most of the components in the PC are small,
especially the screws. Anytime you open the system case, you should do so
in a work area with plenty of direct light. If this is not possible, then have a
reliable flashlight on hand to help you see what you are doing and to help
you find all of the screws you drop inside the case.
Protect the memory module Most memory modules, SIMMs and DIMMs,
come packaged in an antistatic sleeve (see Figure 7-8). Keep all memory
modules in their protective packaging right up to the moment you are ready
to install them. Also, place any removed modules into a protective sleeve
immediately after removing them from the PC, and never stack unprotected
memory modules on top of each other.
Handle modules only by their edges Avoid touching the module’s connectors
and components. It really doesn’t take much in the way of ESD to damage the
module. In fact, ESD you can feel is ten times more powerful than a charge that
will damage an electronic circuit, such as a memory module.