My bios has crashed and my attempts to reset it to factory default by removing battery etc have faild. My system does not boot but the CPU fan spins at a very high speed the moment system is switched on.
I've had the same problem intermittently with 2 Dell GX280 Mini Towers.
Every time I've done the following, the problem went away for quite a while:
1. Remove all memory cards and try booting it (it won't boot with no memory cards anyway, but do not worry).
2. Insert one memory card and try booting (it may now boot ok and if you have only 1 memory card, you are finished and all should be well for quite a while).
3. Insert the 2nd memory card if you have it and again try booting.
4. Keep shutting down power and try to reboot.
At some point in the above steps, the system will start booting ok and usually stay ok for quite a while. Rarely, it might give the problem again soon rather than later and if so, you just repeat the above. I've never had the problem re-appear again quickly more than once or twice in about 4 years.
To be safe, whenever removing or inserting a memory card, be certain the power cord is unplugged and has been unplugged for a few minutes.
If upon bootup, you get a message saying that memory has changed, just hit the key you are told to hit to ignore the change.
I have successfully done this procedure at least 8 times in 4 years.
Lately, when one of my Dell GX280 Mini Towers starts up with high fan speed but otherwise seems dead (no boot screen, can't enter bios setup using F2, etc-really dead other than the fans spinning too fast), if I just leave the machine alone for about 1 or 2 minutes, it seems to recover all by itself and then the regular bootup screens appear. I have no longer had to remove and reinsert memory cards.
So, patience may be all that's needed.
Once the machine finally does bootup, this problem usually does not re-appear for months.