Dell Precision 690 - Manual (Page 124)

ALERT! Cover was previously removed.
6. Reset the chassis intrusion detector by changing Intrusion Alert to Enabled or Enabled-Silent. See Resetting the Chassis Intrusion Detector . The
Chassis Intrusion Switch is actually essential to your computer as that it can alert you if the computer case is unexpectedly removed.
Back to Contents Page
NOTE: If the chassis intrusion switch is not detected or the cover is open the system will run all fans at maximum speed to prevent overheating.
NOTE: If a setup password has been assigned by someone else, contact your network administrator for information on resetting the chassis
intrusion detector.