So I bought a new AC Freezer 7 Pro to replace the stock cooler. I fixed it on, and at first it only works for a few seconds, then shuts off. Of course, I realised it was the thermal shutoff. I saw that the fan had come loose, so I fixed it on, and tried again. Still no joy. I checked the fan once more, and found it was very securely fixed. I tried once more, to find it doesn't power on at all. I get lights on the motherboard, but when I press the button, there is no response whatsoever. (I also tried touching the pins with a screwdriver, just in case the button didn't work)
Now I'm rather confused about this. I know that the processor automatically shuts off when it reaches 85 degrees, so no permanent damage can be caused by faulty cooling. Any ideas anyone?
EDIT
Ah, no I didn't clean off the original paste. I know you normally should, but how could it make that much difference?
FYI, it's a 775 socket, so I simply untwisted the 'spikes' of the stock cooler, then lifted it out, placed in the new cooler (with thermal paste) and pushed in the 'spikes', until it was secured to my satisfaction. I've done quite a few of these in my time, so I'm pretty sure it was well secured.