I am getting the above error message and then everything freezes at boot up. Can anyone help with what to try next?

I've removed the cover and pressed the trip switch manually while bootting. I've cleaned out the entire chasis and made sure all connections are secure. :?:

It's a Dell Optiplex GX1. I know it's old but was working fine to this point.

Any help would be appreciated.

Dani AI

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On OptiPlex-era Dells, that message is driven by a physical chassis-intrusion switch wired to a small header on the motherboard. If the switch or cable is stuck in the "open" state, the BIOS can latch the alert and halt before you ever reach Setup. Also note: on most Dells, F2 enters BIOS Setup and F12 opens the one-time boot menu.

A fast way to isolate the fault is to bypass the switch. With AC power disconnected and after discharging by holding the power button for 10 seconds, locate the tiny plunger-style switch at the case edge and follow its two-wire lead to the motherboard header (often near the front-panel connectors). Reseat the connector. To test, remove that two-wire plug and place a temporary jumper across the two pins on the motherboard header; this simulates the cover being closed. If the system now posts, replace the switch or leave the header jumpered and disable intrusion reporting in BIOS once you can get into Setup. If it still halts, clear NVRAM using the dedicated motherboard jumper next to the coin-cell battery (labels vary by board, such as RTCRST/CLR_CMOS); move it to the clear position for ~10 seconds with power removed, then return it to normal and try again. Faulty front-panel harnesses can also assert the intrusion line, so try booting with nonessential front-panel/optical-drive cables disconnected.

You can look up your exact header and jumper locations in Dell’s service manuals by entering the model at the Dell Support Manuals portal at Dell Support Manuals. Intel also explains how chassis-intrusion circuits are sensed and how jumpers affect them in its general guidance at Intel Support.

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First of all- That alert is an option in the BIOS of Dell computers. Boot into your BIOS setup (hitting the F12 key just after the system restarts gets you there for Dells if I recall) and disable the option.

As to why it freezes, I'm not sure. does it boot properly into Safe Mode?

I did turn the option off (it is alt + F12). But it still is showing the same error. No, I am not able to get into safe mode. I get a little bit of the Dell startup screen and then right into the alert message. I am not even able to get into the BIOS setup any longer.

Any help would be appreciated.

I am not even able to get into the BIOS setup any longer.

Hmm- that's obviously not good.

1. You could try a "brute force" BIOS/motherboard reset:

* Unplug the AC power cord from the machine
* Remove the CMOS battery (the small, flat wristwatch-type battery) from its socket on the motherboard.
* Let the system entirely discharge by leaving it unplugged and with the battery removed for an hour or so.
* Reinstall the CMOS battery, plug the power back in, and start it up again.


2. If the reset doesn't work, remove all non-essential components (extra RAM modules, network card, sound card, CD-ROM drives, etc.) and see if the system boots. If so, start replacing the components you removed one by one. If the system only stalls when one particular component is installed, chances are pretty good that the component is faulty and needs to be replaced.

Since you have physical access to the system (can open it up), all is probably not lost. BIOS protection measures are really only secure if the case is secure - i.e. locked with a combination/key lock. Otherwise, you can usually find a way to reset the BIOS to factory default, thereby clearing any admin or user password in BIOS. The previous poster mentioned some ways to attempt to do this, as well as some good diagnostic techniques. However, many modern motherboards offer a BIOS (also commonly referred to as CMOS) reset option - it is either a button, or a jumper. If it is the button (and I have seen this quite frequently on older Dell motherboards), just press it once & your BIOS should be reset. If it is a jumper, switch the jumper to the clear position (this type of jumper is usually a 3 pin motherboard connection/2-pin jumper bit variety - move the bit from the 2 pins it is on to the other possible 2-pin combination), then power the system on. Then, power the system back down, put the jumper back in its original position, and the BIOS should be reset. In either case (jumper/button), this mechanism should be located near the CMOS battery (looks like a watch battery), and will probably be labelled on the motherboard.


-Matt
Quick PC Repair (serving the San Diego, CA area)
www.quickpcrepair.com

I have found the CMOS battery, but I can't seem to take it out without braking anything. It is in tight!

Nevermind, I found out how. Stupid clamps. =/

I did turn the option off (it is alt + F12). But it still is showing the same error. No, I am not able to get into safe mode. I get a little bit of the Dell startup screen and then right into the alert message. I am not even able to get into the BIOS setup any longer.

Any help would be appreciated.

Hi

I had a similar problem, however turning off the chasis intrusion wasn't enough there is another option in the security menu underneath the chasis intrusion option, its called intrusion alert. I had to 'acknowledg' the intrusion. You won't see intrusion alert option normally, only when chasis intrusion option was turned On AND the cover was removed. Hope that helps

to remove the message '' alert! cover was previously removed''restart the system then press F2, enter bios setup, use the down arrow key to scroll down, there you will find chasis detection or intrusion, use the right arrow key to select '' enabled-silent'' or '' disabled'' which ever you choose , then press ESC to come out, it will restart again automatically, then the error message wont appear again. This message is to inform the owner of intursion detection, to show a managed environment.

i dont have such option, chasis detection or intrusion. what am i supposed to do?

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