Indicates chassis open when booting up - Computers & Internet

might be sensor mulfunction

That just means the case of the desktop was opened by someone.

http://phubner.eng.ua.edu/Files/Optiplex%20GX620/advfeat0.htm#wp1124663

Security Chassis Intrusion Detection NOTE: When the administrator password is enabled, you must know the administrator password before you can reset the Chassis Intrusion setting. This feature, if installed and enabled, detects that the chassis was opened and alerts the user. To change the Chassis Intrusion setting:

1. Enter system setup.
   
   
2. Press the down-arrow keys to move to the System Security option.
   
   
3. Press <Enter> to access the System Security option's pop-up menu.
   
   
4. Press the down-arrow key to move to the Chassis Intrusion setting.
   
   
5. Press <Enter> to select an option setting.
   
   
6. Press <Enter> again after you update the option setting.
   
   
7. Exit and save system setup.
   
   

Option Settings

• On - If the computer cover is opened, the setting changes to Detected, and the following alert message displays during the boot routine at the next computer start-up:
  
  

Alert! Cover was previously removed.

To reset the Detected setting, enter system setup. In the Chassis Intrusion option, press the left- or right-arrow key to select Reset, and then choose On, On-Silent, or Off.

• On-Silent (default setting) - If the computer cover is opened, the setting changes to Detected. No alert message appears during the boot sequence at the next computer start-up.
  
  
• Off - No intrusion monitoring occurs and no messages appear.

Some computers will have a sensor to indicate that your chassis(case) is open. This sensor can get stuck sometimes and you will need to enter BIOS (setup) and reset it. You should be able to disable this feature in BIOS also and I would as it's not really useful other than having the chassis open and screw up the airflow and raise the temp of the computer internals.

Comment if you need further assistance

When you open the computer case, a switch is tripped and after the case has been closed and the computer boots up, you get this chassis intruded message.
To clear this message go to the BIOS configuration and then to the chassis intruder detect and then Reset this setting.

You have to disable the chassis intrusion alarm by going into the BIOS as the machine first starts up, either by pressing Esc or Del, in the BIOS you can then disable the alarm.



Regards.

clear your bios, close very good your case, open bios disable chasisis open detected fro yes to no, (or in some model from enable to disable ) change saves exit booting and good work.

firstly, you have to close the side panel after install any component. if the message show you again, try to find and short connect the jump (2 pins, signed Chassis) on your mainboard.

1. Hit DEL when booting to get into the BIOS
2. Choose PC Health function
3. The first item is the chassis open function - hit Enter to change it to Clear.
4. F10 to exit and save the change
5. Reboot
6. GO into the BIOS again and this time select Disable for the chassis opened function
7. F10 to save and exit
8. Done.
   

There is a mechanical switch connector available to determine if someone has opened the chassis.

You can bypass this through the BIOS by entering the BIOS on bootup (DEL? message at bootup? F1?) then look for the system chassis intruder alarm and DISABLE

Another option is to find the pins that the switch is supposed to be connected to (documentation on the ASUS P4B motherboard) and jumper them.

plz disable the chassis open warning option in the bios.