I built my computer a while back, and I have had this type of issues on and off all the time.
When my computer is actually loading Windows, it works like a charm. The idle temperature is 25-30 degrees (Celsius), 'gaming' temperature is 40-50 degrees and stress test with Prime95 never exceeds 60 degrees.
When I move my computer (I don't know why, but almost every time I attend a LAN-party this problem occurs) it is very little chance for it to load Windows. It usually stops the upstart with a CPU Over temperature failure error (Press F1 to enter BIOS). When I press F1 and enter BIOS, I can see the CPU temperature is somewhere between 95-99 degrees, the odd thing is that the CPU fan speed is 2000-2500 RPM (shouldn't it be more to try fighting the extreme heat?). I have no choice but to power it down and wait for it to cool down. Earlier, replacing the thermal paste has fixed the problem and I could start it normally again.
What happened today was a similar issue... The only difference is that the CPU fan (H80 water cooler) does not appear in the BIOS and the error is CPU FAN NOT FOUND instead of CPU Over temperature failure. I can see the CPU temperature increasing in the BIOS until I have no choice but to power it down again. I can hear and see that the two fans on the radiator is spinning and I can clearly feel, with my hand, that the fans are moving a lot of air.
I plugged the CPU fan in the CHA_FAN2 and one of my chassis fans in CPU_FAN. When I entered BIOS I could see CPU_FAN (which now was the chassis fan) but could not see the CHA_FAN2 (which now was the CPU cooler). Does this mean there is something wrong with the water block (the piece i place on the CPU)?
Is this more likely a BIOS fault or a fault with the water cooler. If it's a BIOS fault, can this be fixed? If this is a water cooler fault, should I replace it?
I HAVE TRIED:
Replacing the thermal paste
Take out and in the RAM
Clean the radiator for dust
Switching the CPU and the chassis fan connector
Checked that there should be no problem for the water to flow in the tubes between the radiator and the water block
Waited before a restart (so there was time for it to cool down)
I appreciate your answer! -Espen