signs of a blown processor

I do repair services for people, and usually i can tell just by a few seconds whats wrong, but this is different. The system seems to start getting power (the fans start spinning), but it then immediately turns off. i thought at first it was a blown Mobo, but theres no way to tell since the system never reaches the bios. I think it might be the processor, but i don't know any of the signs of a blown proc. Any input would help.

O btw, when it came and i opened it the CPU heatsink was not on the CPU, it was hanging....

But don't most systems have failsafes to keep CPU's from overheating(mine does)?

The heatsink was "hanging" ?
Did they mess with anything other than that ?

I had a system do that once, I don't remember exactly what was wrong, but it wasn't blown, it had somthing to do with how I had power/switch wires hooked up for an ATX power supply.

I bet that there is damage to the mother board. I've seen 3 PCs like that where there was an abrupt shutdown. If they are willing to pay the price, I would buy a bundled mobo and CPU from tirgerdirect or another supplier.

Many Mobos have a feature called "shutdown temperature". On reaching a particular temperature usually 60 degree celcius, system gets off automatically. Its a protection for the Processor when the Heatsink fails to maintain the the temperature.

Yes, Ive seen this before It happened to my old dell in fact.
I'm pretty sure its a motherboard issue

When I had this problem I suspected the Power supply so i replaced it and still same thing.

Tried the same thing with ram still the same thing.

So if possible try to get a hold of another processor of the same socket and see if anything happens.

I concur with previously stated shutdown based on a thermal overload of the processor ... without that heatsink on there the system should shut down within seconds ( done this myself once before and i'm semi-ashamed to admit it)

edit; my apologies on reviving an older thread

This sort of symptom will sometimes occur when the BIOS settings are too far advanced for the hardware that the mobo does an auto shutdown before even getting to the BIOS ID screen.

Follow the procedure (pull jumper) that sets the BIOS back to the factory settings and see what effect, if any, it has had.

Good Luck.