Dell OptiPlex 330, Service Manual

Page: 12 / 170

12
Before You Begin
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Precautionary Measures
Before you remove the computer cover, perform the following steps in the
sequence indicated.
1
Turn off your computer and any peripherals.
2
Disconnect your computer and peripherals from their power sources.
Also, disconnect any telephone or telecommunication lines from the
computer.
Doing so reduces the potential for personal injury or shock.
3
If you are disconnecting a peripheral from the computer or are
removing a component from the system board, wait 10 to 20 seconds
after disconnecting the computer from AC power before
disconnecting the peripheral or removing the component to avoid
possible damage to the system board.
4
Wear a wrist grounding strap, and clip it to an unpainted metal
surface, such as the padlock loop on the back of the chassis. If a wrist
grounding strap is not available, touch any unpainted metal surface on
the back of the computer or on the computer chassis, such as the
power supply, to discharge any static charge from your body before
touching anything inside the computer. While you work, periodically
touch an unpainted metal surface on the computer chassis to dissipate
any static electricity that might harm internal components. Also avoid
touching components or contacts on a card and avoid touching pins on
a chip.
5
Verify that the standby power indicator on the system board is not on.
If it is on, you may need to wait 10 to 30 seconds for it to go out. To
locate this indicator, see " System Board Components " or " Interior
Service Label ."
Recommended Tools
Some of the procedures in this document require the use of a #2 Phillips-
head screwdriver.
Also, use a wrist grounding strap as explained in " Precautionary Measures ."