CPU overheating

[reddevilggg]

I have recently fitted an Athlon AMD 64 x2 dual core processor. When I try to boot up the computer the CPU temperature rises to 80 degrees C + and then the computer automatically shuts down.

The processor replaces an Athlon 64. Before buying the new one I checked compatibility with the motherboard - all fine. (Checked this on the manufacturer website)
I have cleaned the replacement CPU and applied thermal paste (Arctic Silver 5) according to all recommendations. I have checked voltages and although these are different for the replacement CPU, I am unable to change these in the BIOS and it seems that this is automatic. The old CPU should have a voltage of between 1.35 and 1.40 volts and the replacement one should have a voltage of between 1.30 and 1.35 volts. I haven't had a chance to check the voltage of the replacement CPU as the computer won't stay on long enough for me to run CPUid.

I have reset the BIOS, doesn't seem to affect anything.

When I first loaded the replacement CPU the system recognised it and loaded device drivers straight away.

I have also checked that the processor, heatsink and fan are installed correctly and have managed to get into the BIOS long enough to see that the fan speed starts at about 2000 rpm and goes quickly up to around 4500 rpm as the temperature rises. This was checked with Speedfan.

I have put the original CPU back in and everything works okay again. I have also tried various combinations involving the replacement CPU, my old heatsink and the new fan, my old fan and the new heatsink etc.

I have started the computer in diagnostic mode with most of the start up applications shut down and this has made no difference.

The replacement CPU is secondhand, could this be a problem?

Any other ideas?

Thank you!

Motherboard: Asus A8AE-LE (AmberineM)
Socket 939
Windows XP (SP3)
PSU: Thermaltake 750 watt
3GB RAM

[Alan]

Hi reddevilggg
Well it seems as though you have gone trough all the correct steps of trying to eliminate the problem. My first thoughts lent towards the CPU fan, but you have ruled that out!
As I see it, it is either the MOBO not liking the new CPU or as you say the new (second hand ) CPU is at fault.
I don't suppose you have the option of trying the new CPU on anther system do you?

[Boyd]

Sounds like mostly the 2nd hand CPU problem...if you have turning fan and real heat sink then should have no CPU overheat problem which exist 80c...

if fan not turning well or heatsink not work good then normally it should just straight up to around 65c or something

If the motherboard sensor problem then it will not detect the temperatute tooo

I think you better try with another new CPU Processor instead....

Good luck and post back your result