Dell OptiPlex SX Systems, Setup And Quick Reference Manual

Page: 11 / 108

S e t u p a n d Q u i c k Re f e r e n c e G u i d e 9
When Using Your Computer
As you use your computer, observe the following safe-handling guidelines.
CAUTION: Do not operate your computer with any cover(s) (including computer covers,
bezels, filler brackets, front-panel inserts, and so on) removed.
• Your computer is equipped with one of the following:
– A fixed-voltage power supply — Computers with a fixed-voltage power supply do not have a
voltage selection switch on the back panel and operate at only one voltage (see the regulatory
label on the outside of the computer for its operating voltage).
– An auto-sensing voltage circuit — Computers with an auto-sensing voltage circuit do not have
a voltage selection switch on the back panel and automatically detect the correct operating
voltage.
– A manual voltage selection switch — Computers with a voltage selection switch on the back
panel must be manually set to operate at the correct operating voltage.
Set the switch to the position that most closely matches the voltage used in your location.
NOTICE:
To help avoid damaging a computer with a manual voltage selection switch, set the switch for the
voltage that most closely matches the AC power available in your location. For Japan, the voltage selection
switch must be set to the 115-V position even though the AC power available in Japan is 100 V. Also, ensure
that your monitor and attached devices are electrically rated to operate with the AC power available in your
location.
• Before working inside the computer, unplug the computer to help prevent electric shock or system
board damage. Certain system board components continue to receive power any time the computer
is connected to AC power.
When Working Inside Your Computer
Before you open the computer cover, perform the following steps in the sequence indicated.
CAUTION: Do not attempt to service the computer yourself, except as explained in your
online Dell™ documentation or in instructions otherwise provided to you by Dell. Always
follow installation and service instructions closely.
NOTICE:
To help avoid possible damage to the system board, wait 5 seconds after turning off the computer
before removing a component from the system board or disconnecting a device from the computer.
3U083ebk3.book Page 9 Friday, July 25, 2003 10:32 AM