Is this supposed to happen: I removed a Socket 478 CPU to replace with another CPU and when I did remove the heatsink, to my surprise, the CPU was still attached to the heatsink from the thermal grease. How do I separate the CPU and heatsink? I tried adding Metholated Spirits/95% alcohol to it but it doesn't unstick!

That's pretty common If you can put the CPU back in, run the machine for a couple of minutes, then give the heatsink a gentle twist to remove it. If you can't/don't want to plug it back in, heating the heatsink with a hair dryer for 30 seconds, then twist off the CPU, will do the trick. A credit card wedged into the CPU to budge it off also helps.

If it's a stock Intel heatsink, make sure you remove all the tin foil and heatsink crud (best removed with acetone) and reapply a thin layer of thermal paste.

JB

Byrd is correct, you need to heat it up so the thermal compound becomes soft, then just twist slightly while you're removing to break the seal.

I 'fixed' it by using a flathead screwdriver to peel apart the CPU. I be talking to that store when it reopens to ask why they applied so much thermal paste until it bonded the whole thing together.

Now how am I supposed to clean off the thermal paste? I can't hold it by the corners and clean it. I don't have a anti-static wrist strap on me. My desk is on carpet. What can I place the pin side on?

It's not their fault - stock Intel and AMD heatsinks usually come with a huge wad of TIM (thermal interface material) that can often act like glue and be very hard to remove the CPU for the first time. The TIM is only single use, so once chiselled off you can replace it with some Arctic Silver or white silicone grease.

JB

clean it with metho.

Also, it wouldn't have been them who applied it, many heatsinks come with the thermal compound applied from the factory.

If it's thick and glue-like, acetone - the nail polish remover you get from your local supermarket will be fine. Gently using a razor blade (on the heatsink, not the CPU!!) can also help (usually for the AMD TIM, probably not required for an Intel TIM). You don't need an anti-static strap - I've never used one - just ground yourself by touching the metal computer case, which should be plugged into the wall (switched off). You can then begin cleaning it up, holding onto the sides and not near the pins.

JB

Never said it was- I meant I was going to buy some more thermal grease and ask them to also warn people about heatsinks sticking to CPUs.

Curious to see, but if some Ethanol has touched some of the pins, is it damaged?

To most computer builders, in their mind more thermal paste = a good thing. Apple have been guilty of this in the past too (most recently first generation Macbook Pros!). Or, it will come with next to no paste at all (common in video cards for some reason).

Acetone touching the pins will not cause any issue, and it will evaporate within seconds. To be sure, I generally wipe the CPU down with an Isopropyl Alcohol wipe to make sure it's properly cleaned, to finish off. Double-check that no grease has ended up on the pins too

JB

Fixed within half an hour. I should have came and posted here first, after hours of trying to fit the damn thing into the motherboard with the heatsink. Didn't see that there's a small shiny lever that meant only the CPU can come in.

Now, I wait anxiously to see if it still works- I touched the CPU with a nail when I was ungrounded.

Can I run power on the PC with the heatsink buy without applying thermal paste for a few seconds? I really need a definitive answer.

I wouldn't, as a rule. You can - Intel P4 CPUs have thermal throttling which will downclock the CPU speed if overheating - but older CPUs (especially Athlon XPs) do not have this feature, and will fry with seconds if a proper heatsink + fan + thermal paste is not applied.

So, best to apply some of that cheap white silicone paste that is easy to install, and put gentle pressure on the heatsink as you turn on the machine (no need to bolt it down), to make sure there is sufficient contact to prevent overheating.

JB

and current iMacs and Macbook's.
The Macbooks were the worst!

Ok. I just booted it. It stayed on for 5 seconds and the fan was extremely loud. I didn't see POST or Power On Self Test, it just had a black screen for 4 seconds and a very brief Windows XP boot screen. Is this normal? The same thing happened when I overclocked the Pentium 4, no POST, just XP boot. Remember, there's no thermal paste on it...