Overheating problem with PC

[tweaky]

I recently upgraded my sisters pc to an XP2400+ using an EPoX 8k3a+ motherboard that I had lying around but everytime I enabled the temperature alarm sensors/shutdown feature in the bios, which I set to 65C, the thing will shut itself down after 5 minutes or so of relatively idle activity, despite the fact the bios and sandra etc. are showing temps around the 40C mark?
She is using a SK-6/TT 60mm fan pushing around 32cfm to cool it with (bit old I know), and upon touching it doesn't feel hot to touch at all, only relatively warm at best.

So anyway I decided to update the bios to the latest official version, 3409 I beleive, and lo and behold the temps shot up from a previous reading of 40C to a whopping 75C . So I am thinking ok no wonder it has been shutting itself down all the time, but even still the heatsink only feels very warm to touch at best, not even hot in the slightest. I installed the USDM epox temp monitoring program and it is reporting temps of 80C at load during a 3DMark run. Its a bit weird really seeing this kind of behaviour, I mean there is no funny smells coming from the PC whatsoever to suggest that the CPU could be slowly burning away, so what do you think, could those temps be for real, especially considering the cooling that is being used?

[hchu]

Normally the heatsink should be really hot so the interface material between the processor and heatsink is definitely not working right. Reinstall the thermal interface, read AMD's guide on processor and heatsink installation.

[tweaky]

Originally Posted by hchu

Normally the heatsink should be really hot so the interface material between the processor and heatsink is definitely not working right. Reinstall the thermal interface, read AMD's guide on processor and heatsink installation.

I have already reinstalled it twice now, applying more and then less artic silver 3 on the core, but alas it is still the same. Oh well if the PC remains stable then I am not really going to worry, with temps like that the thing wouldn't exactly be very stable anyway.

[LP]

Originally Posted by tweaky

So anyway I decided to update the bios to the latest official version, 3409 I beleive, and lo and behold the temps shot up from a previous reading of 40C to a whopping 75C .

Could be there's a problem with the new bios reading temps right.

[tweaky]

Originally Posted by LP

Could be there's a problem with the new bios reading temps right.

Lets hope so