Restarting The System; Computer Cover - Dell Precision WorkStation 420 Service Manual

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 light-emitting diode (LED) 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 (see

Restarting the System

To restart the system and reset the chassis intrusion detector, perform the following steps:
1. Replace the computer cover and reconnect the computer and peripherals to their power sources and turn them on.
NOTE: When you start the system, the chassis intrusion detector will cause the following message to be displayed at the next
system start-up:
ALERT! Cover was previously removed.
2. To reset the chassis intrusion detector, enter System Setup, select System Security, and reset Chassis Intrusion to Enabled or
Enabled-Silent.
NOTE: If a setup password has been assigned by someone else, contact the network administrator for information on resetting the
chassis intrusion detector.

Computer Cover

Figure 1. Computer Cover Removal
To remove the desktop chassis computer cover, perform the following steps:
1. Turn off your computer and peripherals, and observe the Caution for Your Personal Safety and Protection of the Equipment described in
"Precautionary Measures."
2. If you have installed a padlock through the padlock ring on the back panel, remove the padlock.
3. Press in on the two securing buttons until the cover is free to swing up (see
4. Raise the back of the cover, and pivot it toward the front of the computer.
5. Lift the cover off the hooks at the front of the chassis.
Figure 2. Computer Cover Replacement
Figure 22 or the internal service label).
1 Securing buttons (2)
Figure 1).