Dell Precision WorkStation 420 Service Manual page 40

1 Chassis intrusion cable connector
2 Control panel chassis intrusion connector
3 Enlarged hole for cable
4 Switch slot
5 Chassis intrusion switch
CAUTION: Before you remove the computer cover, see
To remove the chassis intrusion switch and install a replacement, perform the following steps:
1. Disconnect the chassis intrusion switch cable from the control panel (see Figure
Note the routing of the chassis intrusion cable as you remove the cable from the chassis. The cable is routed through an enlarged hole in the
chassis and through a hole in the disk-drive cage door. The chassis intrusion switch is mounted on the left front of the chassis (see
Figure 26).
2. Slide the chassis intrusion switch out of its slot on the chassis and carefully remove the switch and its attached cable from the chassis.
3. Install the replacement chassis intrusion switch and cable.
4. Replace the computer cover. Then reconnect your computer and peripherals to their power sources, and turn them on.
NOTE: After you remove and replace the cover, the chassis intrusion detector will cause the following message to be displayed at
the next system start-up:
ALERT! Cover was previously removed.
5. To reset the chassis intrusion detector, enter System Setup, select System Security, and reset Chassis Intrusion to Enabled or
Enabled-Silent (see your User's Guide for instructions).
Power Supply
To access some components on the system board, you may have to rotate the system power supply out of the way. Use this procedure to rotate
the supply out of the chassis, or to completely remove it.
To rotate or remove the power supply, perform the following steps.
CAUTION: Before you remove the computer cover, see
1. Remove the computer cover.
2. Lay the computer on its right side (as viewed from the front).
3. Disconnect the AC power cable from the AC power receptacle on the back of the power supply (see
Figure 27. Rotating the Power Supply
"Precautionary Measures."
26).
"Precautionary Measures."
Figure 27).