If you receive an error message saying Chassis Intruded, Fatal Error … System Halted on the monitor; it means that the Chasis or the cabinet which holds the motherboard, CPU, GPU, etc. is open. It’s a security feature offered by some OEMs where a connector found on a motherboard can detect if the chassis component has been removed or replaced. Some OEMs also offer onboard speaker or PC chassis speaker which goes off in situations like these.
Chassis Intruded! Fatal Error … System halted
This is a hardware problem, and in most of the situations, you need to put the jumper back on the motherboard with the pin labeled chassis signal and ground. Sometimes OEM offers a simple switch which is automatically armed when you close the chassis properly. So check if that’s the problem you are facing.
If this is not solving your problem, and while you may be able to get into Windows with a warm boot, normal Windows Boot doesn’t work. It’s rather false positive, and something to do with the state of RTC RAM or BIOS. You may have to disable the Chassis intrusion feature completely to get rid of this error message.
1] Clear CMOS: This can easily be done by shorting two pins which are on the motherboard side by side. It may vary from OEM to OEM, but the basics remain the same to the clear CMOS. You may have to download the manual from OEMs website to find the pin location.
2] Boot into BIOS: Start your computer and press DEL or F2 key to get into BIOS. Everything will be set to default after you reset CMOS.
3] Disable Chassis intrusion: Find Chassis intrusion feature in your BIOS. It could be under security and disable that feature.
4] Re-configure BIOS: After disabling the Chassis feature, you will have to reconfigure your BIOS the way you expected it to be or it was before the reset.
This should help you fix the issue with Chassis intrusion. If you are still not able to fix it, you may have to remove the wires responsible for intrusion detection. The information for this will be available in the manual of the motherboard.