Dell Precision 410 User Manual page 197

To reduce the possibility of EMI and RFI, follow these guidelines:
Operate the system only with the computer cover installed.
Ensure that all expansion slots are covered either by a card-mounting bracket or
by a metal filler bracket and that all drive bays have a drive and/or a metal insert
installed. These brackets and metal inserts are available from Dell.
Ensure that the screws on all peripheral cable connectors are securely fastened
to their corresponding connectors on the back of the computer.
Always use shielded cables with metal connector shells for attaching peripherals
to the computer.
To prevent the possibility of RFI from a computer affecting TV reception, follow these
guidelines:
Keep any TV set at least 6 ft away from the computer system.
Use cable TV when possible.
Use a directional outdoor TV antenna.
Attach line filters to the TV set.
Use 75-ohm coaxial cable for the TV set rather than twin-lead antenna wire.
If interference occurs, rotate the computer or the TV set 90 degrees.
Because they store data magnetically, diskettes and hard-disk drives are extremely
susceptible to the effects of magnetism. Diskettes should never be stored near mag-
netic sources such as the following:
Monitors
TV sets
Printers
Telephones with real bells
Fluorescent lights
Excessive shock can damage the function, external appearance, and physical struc-
ture of a system. Each Dell system has been designed to operate properly after
withstanding a minimum of six consecutively executed shock pulses in the positive
and negative x, y, and z axes. Each shock pulse can measure up to 50 gravities (G)
(half-sine wave) for up to 2 milliseconds (ms). In storage, the system can withstand
shock pulses of 110 G (half-sine wave) for 2 ms or 27 G (square wave) for 15 ms.
Excessive vibration can cause the same problems as mentioned earlier for shock, as
well as cause components to become loose in their sockets or connectors. Systems
can be subject to significant vibration when being transported by vehicle or when
operated in an environment with machinery that causes vibration.
Maintaining the System D-7