X20/X21 heatsink

[icebag]

I have just bought an X21 in an X20 chassis. Nice machine, but it switches itself off from time to time and I suspect overheating.

When I take the heatsink / fan unit off the processor there is an area of yellow where the heatsink touches the processor. This I guess is a thermal pad of some sort, or maybe thermal gel.

Anyway, the yellow area has a hole in it that I guess should not be there. Should it be a solid rectangle of yellow? If so, what do I do to fix it?

All help gratefully received.

[icebag]

Well, to answer my own question, I have bought some heatsink compound that I will use to fill in the hole. Better still, I think I will remove the yellow substance and start again.

I will report back here on whether it cures the switching off problem.

[icebag]

I removed the yellow reside from the heatsink and cleaned the surface with isopropyl alcohol.

Then I applied thermal compound (costing 2 GBP = 4 USD on eBay) to the cpu and screwed the heatsink back in place.

The machine has now been running about 3 hours without switching itself off. A cpu temperature monitor program is giving readings in the range 60-65 C, comfortably below the limit for a Pentium III.

So, fingers crossed, the problem might have been solved.

[John Henry]

Good job, sounds like you fixed the problem. AFAIK, the thermal grease should cover the whole contact surface area.

[cofreth]

Is it advisable to use a lappy cooler pad if you are going to use it for 3 hour or more under ambient temperature of around 32 degree C or 90 degree F?

[The Spirit of X21]

Is it advisable to use a lappy cooler pad if you are going to use it for 3 hour or more under ambient temperature of around 32 degree C or 90 degree F?

You don't have to; it's really a matter of personal preference. If it's too hot for you, use one. If not, don't worry about it.

[tom_k]

The cooler pad in X20/21 between die and fan unit has aluminium foil up and down
and that yellow stuff between it which seems to degrade with heat and time.
The "pad" is about 0.4mm thick and i do strongly advise not to use only grease to fill this gap,
i got much better results with the thermal rubbers from
T20 models
basically i don`t like them, thats why i always exchange the "small" T20 fan with the model that gives direct contact with the die.
My X21-700 board came with fan unit that had the pad removed but a big amount of AS5 in Place. i also had temps above 60°C,
imo too much, with thermal rubber(do not add grease!) its about 51 to 53 °C, similar results with X20s

[icebag]

Thank you Tom_K, I will bear this in mind if I have further problems. Just for information, the machine has now been in use every day since the fix and it hasn't crashed once.