Datasheet

46 Chapter 1
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Hardware
RAID 5 Combines the benefits of both RAID 0 and RAID 1, and is known as Striping
with Parity. It uses a parity block distributed across all the drives in the array, in addition
to striping the data across them. That way, if one drive fails, the parity information can be
used to recover what was on the failed drive. A minimum of three drives is required.
Firmware
Any software that is built into a hardware device is called firmware. Firmware is typically
in flash ROM and can be updated as newer versions become available. An example of firm-
ware is the software in a laser printer that controls it and allows you to interact with it at
the console (usually through a limited menu of options).
Daughterboards
Any boards added to the motherboard to expand its capabilities are known as daughter-
boards (“daughters” of the “mother”). A common use is to insert one daughterboard (also
called daughter boards) into the motherboard and allow expansion cards to then be inserted
into it sideways, thus saving space.
Motherboard and CPU Problems
Most motherboard and CPU problems manifest themselves by the system appearing com-
pletely dead. However, “completely dead” can be a symptom of a wide variety of problems,
not only with the CPU or motherboard but also with the RAM or the power supply. So,
a POST card (described in the preceding section) may be helpful in narrowing down the
exact component that is faulty.
When a motherboard fails, it’s usually because it has been damaged. Most technicians
can’t repair motherboard damage; the motherboard must be replaced. Motherboards can
become damaged due to physical trauma, exposure to electrostatic discharge (ESD), or
short-circuiting. To minimize the risk of these damages, observe the following rules:
Handle a motherboard as little as possible, and keep it in an antistatic bag whenever
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it’s removed from the PC case.
Keep all liquids well away from the motherboard, because water can cause a short circuit.
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Wear an antistatic wrist strap when handling or touching a motherboard.
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When installing a motherboard in a case, make sure you use brass stand-offs with
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paper washers to prevent any stray solder around the screw holes from causing a short
circuit with the metal of the screw.
A CPU may fail because of physical trauma or short-circuiting, but the most common
cause for a CPU not to work is failure to install it properly. With a PGA-style CPU, ensure
that the CPU is oriented correctly in the socket. With an SECC-style CPU, make sure the
CPU is completely inserted into its slot.
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