Hardware Reference
In-Depth Information
host must be kept running at all times. To save power, turn off its monitor(s) and configure its
power management to slow down the processor and other components when idle. In many
cases you can still have the system enter Stand-By or Hibernate modes, as long as you have
Wake-on-LAN enabled (check the BIOS Setup) so that the system can resume when a remote
access session is initiated.
You should also configure host systems that use logins to not install Windows updates
automatically because some updates restart the system, so the system will not be available to
host remote connections until a user logs into it. For these systems, make sure you set up a
schedule for installing downloaded updates to ensure that the system is available for remote
access and is as up to date as possible.
Static Electricity
Static electricity or ESD can cause numerous problems within a system. The problems usually appear
during the winter months when humidity is low or in extremely dry climates where the humidity is
low year-round. In these cases, you might need to take special precautions to ensure that your PC is
Systems
,” for more information on ESD.
Static discharges outside a system-unit chassis are rarely a source of permanent problems within the
system. Usually, the worst possible effect of a static discharge to the case, keyboard, or even a
location near the computer is a system lockup. Most static-sensitivity problems are caused by
improper grounding of the system power. Be sure you always use a three-prong, grounded power
cord plugged in to a properly grounded outlet. If you are unsure about the outlet, you can buy an outlet
tester, such as those described earlier in this chapter, at most electronics supply or hardware stores
for only a few dollars.
Power-Line Noise
To run properly, a computer system requires a steady supply of clean, noise-free power. In some
installations, however, the power line serving the computer also serves heavy equipment, and the
voltage variations resulting from the on/off cycling of this equipment can cause problems for the
computer. Certain types of equipment on the same power line also can cause voltage spikes—short,
transient signals of sometimes 1,000V or more—that can physically damage a computer. Although
these spikes are rare, they can be crippling. Even a dedicated electrical circuit used by only a single
computer can experience spikes and transients, depending on the quality of the power supplied to the
building or circuit.
During the site-preparation phase of a system installation, you should be aware of these factors to
ensure a steady supply of clean power:
• If possible, the computer system should be on its own circuit with its own circuit breaker. This
setup does not guarantee freedom from interference, but it helps.
• The circuit should be checked for a good, low-resistance ground, proper line voltage, freedom
from interference, and freedom from brownouts (voltage dips).
• A three-wire circuit is a must, but some people substitute grounding-plug adapters to adapt a
grounded plug to a two-wire socket. This setup is not recommended; the ground is there for a
reason.
