I was having problems with overheating, so removed the fan and heatsink from on top of my processor and gave them a good clean (they were covered in dust, particularly the heatsink which I've never really cleaned).

Obviousy I then needed to replace the processor add thermal compound and replace the processor on top which I have done. Carefully.

Now the computer will not boot. It powers up, the fans go on, the hard drive spins, it gets as far as recognising the processor (Intel pentium 4etc comes up on screen) then it freezes.

Did I kill my processor? Might it be something else causing the problem?

"Obviousy I then needed to replace the processor add thermal compound and replace the processor on top (????) which I have done."

The way I read your statement is that you have replaced the CPU with a new/different one.

And what do you mean by replace the processor on top? The fan/heatsink go on top of the CPU. (Or in front of the CPU in slot type mounted processors.)

If this is the case, is the "new" CPU compatable with the motherboard?

Is the CPU fully/properly seated in the ZIF connector or slot?

Is the fan/heatsink assembly firmly clamped down to the CPU ZIF/slot?

Have you altered any bios settings (or removed the CMOS/motherboard battery)?

It's also possible you may have applied too much thermal compound. Here's a couple of guides and related information;

http://www.heatsink-guide.com/compound.htm

http://www.arcticsilver.com/arctic_s...structions.htm

http://www.hardwaresecrets.com/article/274/2

http://www.brian1.net/computers/grease/

http://www.devhardware.com/c/a/Hardw...ermal-Paste/1/

Post back to clarify the above questions.

Sorry, clarification:
Processor is the same one as before, not new.
It is firmly pressed down into the connector, with the lever down.
The heat sink is, of course, on top of the CPU, with the fan on top of that, as you would expect. Just had a bit of brain freeze when writing....
The heatsink/ fan assembly is securely fastened in the original cradle. I suppose I may have applied a little too much pressure initially when getting the heatsink off as it was securely glued to the CPU.
I've neither changed any BIOS settings or removed the CMOS battery.

All i did was remove the heatsink and CPU and put them back, but I definitely used too much thermal compound, based on the articles you linked to. I certainly used more than a grain of rice!!!

Thanks for replying.......

Has the problem gone away after removing the excess thermal paste?

If not, have a look at this article on POST/booting problem troubleshooting:

http://www.d-a-l.com/articles/library/34.html

Sorry for long delay on reply; I've been away on business.

Computer now sorted and booting happily. Excess thermal paste certainly was a problem and the boot went further when I'd sorted that, but I had to strip it down and replace stuff, turned out that the floppy drive was the problem. Never use it any more so not a problem.

Thankyou for your help, I'll be back...........