White thermal paste fails on 478 cpu ?

[Cyberat_88]

Recently removed and reinstalled mb - ECS PT800CE-A1.1 with 478 Prescott CPU, attempted to add a new heatsink and fan, temps went to 90C before shutdown. Decided to go back to original heatsink and fan using new brackets (old ones broke) and I am still having an overheating problem, going to 76C+ idling before shutdown. Normally this system would operate between 45C-55C or 60C+ at loads. Nothing is different at this point except the thermal compound, I had silver originally, this one is white.

 

[Ubrales]

You identified the problem. Re-seat the heatsink using Arctic Silver 5 thermal compound according to industry accepted procedures.

 

[Cyberat_88]

Thanks for the confirmation will get some, need new brackets again, broke the "metal" ones (probably zinc).

 

[Ubrales]

Get some better brackets, and not the same old type.

 

[Leaps-from-Shadows]

Okay. Let me get this straight...

Original heatsink and original brackets = 60ºC.
<brackets break>
New heatsink and new brackets = 90ºC.
Original heatsink and new brackets = 76ºC.

Is that correct?

Unless the white stuff you applied isn't thermal compound at all, switching to Arctic Silver 5 wouldn't make that much of a difference. I'm thinking that the new brackets are the culprit -- they aren't installed right or don't fit correctly or something.

 

[Cyberat_88]

Yes that is correct Leaps, the compound is AS Ceramique and is 2.5g vs. AS 5 which is 3.5g. May have applied too much of it too, so I removed and cleaned again, braking the zinc brackets from the new heatsink as well. Living in CO.S. makes it harder to find a decent PC store, newegg no longer delivers to P.O.B.s. Need to find a way to deliver. The original intel brackets worked fine, my fault for not removing them properly.

 

[Cyberat_88]

Best answer selected by Cyberat_88.

 

[Ubrales]

Thank you!