Before Working Inside Your Computer; Removing The Computer Cover - Dell Dimension YH242 Owner's Manual

Before Working Inside Your Computer

Use the following safety guidelines to help protect your computer from potential damage and to help
ensure your own personal safety.
CAUTION:
Before you perform any of the procedures in this section, follow the safety instructions in the Product
Information Guide.
CAUTION:
Handle components and cards with care. Do not touch the components or contacts on a card. Hold a
card by its edges or by its metal mounting bracket. Hold a component such as a processor by its edges, not by its
pins.
CAUTION:
When working inside the computer, be aware that the processor heat-sink assembly, power supply,
graphics card, and other components may be very hot during normal operation. Be sure that they have sufficient
time to cool before you touch them.
NOTICE:
Only a certified service technician should perform repairs on your computer. Damage due to servicing
that is not authorized by Dell is not covered by your warranty.
NOTICE:
When you disconnect a cable, pull on its connector or on its strain-relief loop, not on the cable itself.
Some cables have a connector with locking tabs; if you are disconnecting this type of cable, press in on the locking
tabs before you disconnect the cable. As you pull connectors apart, keep them evenly aligned to avoid bending any
connector pins. Also, before you connect a cable, ensure that both connectors are correctly oriented and aligned.
NOTICE:
To avoid damaging the computer, perform the following steps before you begin working inside the
computer.
1 Turn off your computer (see "Turning Off Your Computer" on page 77).
NOTICE:
To disconnect a network cable, first unplug the cable from your computer and then unplug it from the
network wall jack.
2 Disconnect any telephone or telecommunication lines from the computer.
3 Disconnect your computer and all attached devices from their electrical outlets, and then press the
power button to ground the system board.
NOTICE:
Before touching anything inside your computer, ground yourself by touching an unpainted metal surface,
such as the metal at the back of the computer. While you work, periodically touch an unpainted metal surface to
dissipate any static electricity that could harm internal components.

Removing the Computer Cover

CAUTION:
Before you perform any of the procedures in this section, follow the safety instructions in the Product
Information Guide.
CAUTION:
To guard against electrical shock, always unplug your computer from the electrical outlet before
removing the cover.
78
Removing and Installing Parts