Dell OptiPlex 740 - Manual (Page 198)

Small Form Factor Computer
Replacing the Chassis Intrusion Switch
1. Gently slide the chassis intrusion switch into its slot and reconnect the cable to the system board.
2. Replace the computer cover (see Replacing the Computer Cover ).
Resetting the Chassis Intrusion Detector
1. Turn on (or restart) your computer.
2. When the blue DELL™ logo appears, press immediately.
If you wait too long and the operating system logo appears, continue to wait until you see the Microsoft® Windows® desktop. Then shut down your
computer and try again.
3. Select the Chassis Intrusion option and then press the left- or right-arrow key to select Reset. Change the setting to On, On-Silent, or Disabled.
4. Press , press the left- and right-arrow keys to highlight Save/Exit, and then press to restart the computer and implement your changes.
NOTE: The default setting is On-Silent.