Chipset fan/heatsink question

The original chipset fan on my A8N-E failed when the mobo was still in
warranty and Asus sent a replacement fan free. Now the replacement has
failed after only a year or so, and I bought a Zalman Northbridge
heatsink to replace it.

My question is: what should I use to remove the old gunk from the
chipset before installing the heatsink (which came with a tube of
thermal grease)?

Perce

Percival P. Cassidy wrote:
> The original chipset fan on my A8N-E failed when the mobo was still in
> warranty and Asus sent a replacement fan free. Now the replacement has
> failed after only a year or so, and I bought a Zalman Northbridge
> heatsink to replace it.
>
> My question is: what should I use to remove the old gunk from the
> chipset before installing the heatsink (which came with a tube of
> thermal grease)?
>
> Perce

A lot of people use isopropyl or rubbing alcohol. That seems to be
safe for electronics packaging (alcohol based cleaners are used for
removing flux from boards). It tends to smear the waste products
around, and isn't really the right solvent for the job.

This stuff is blended a bit more with solvent properties in mind.
It consists of two components, of which apparently, you use a lot
more of one bottle than the other. I've never tried it. Check the
reviews to see what people think of it.

http://www.newegg.com/Product/Produc...82E16835100010

Beware when replacing active cooling solutions with passive ones.
There was a time, when manufacturers put heatsink+fan on 2W chipsets,
which was silly. Those chips would have been adequately
cooled by a Zalman passive. But depending on the chipset now,
some of them are in the 15-20W range. The fan on those may have
been barely adequate.

These are numbers for some Aavid heatsinks. This tells you, that
adding a fan to the Zalman, improves thermal resistance by a
factor of three.

Length Width Height still with
mm mm mm air fan
theta 200LFM

35x35 374624B60024 35.00 35.00 10.00 23.40 7.55 Black anodize
35x35 374724B60024 35.00 35.00 18.00 15.30 5.15 Black anodize
35x35 374824B60024 35.00 35.00 25.00 12.00 4.27 Black anodize

This one has a theta_R of 1.25C/W. It has a fan.

http://www.swiftnets.com/products/mcx159-CU.asp

35C + 1.25C/W * 15W = 54C

35C + 12.0C/W * 15W = 215C

35C + 4.27C/W * 15W = 99C (close to the limit)

Ideally, you'd want a working temperature readout, so you can determine
how well the new solution is working. Waiting for the system to crash,
isn't a very accurate indication of what temp you're at.

Paul

Paul wrote:

>> The original chipset fan on my A8N-E failed when the mobo was still in
>> warranty and Asus sent a replacement fan free. Now the replacement has
>> failed after only a year or so, and I bought a Zalman Northbridge
>> heatsink to replace it.
>>
>> My question is: what should I use to remove the old gunk from the
>> chipset before installing the heatsink (which came with a tube of
>> thermal grease)?
>>
>> Perce
>
> A lot of people use isopropyl or rubbing alcohol. That seems to be
> safe for electronics packaging (alcohol based cleaners are used for
> removing flux from boards). It tends to smear the waste products
> around, and isn't really the right solvent for the job.

Isopropyl alcohol didn't seem to touch it. Goo-Gone worked.

> This stuff is blended a bit more with solvent properties in mind.
> It consists of two components, of which apparently, you use a lot
> more of one bottle than the other. I've never tried it. Check the
> reviews to see what people think of it.
>
> http://www.newegg.com/Product/Produc...82E16835100010
>
> Beware when replacing active cooling solutions with passive ones.
> There was a time, when manufacturers put heatsink+fan on 2W chipsets,
> which was silly. Those chips would have been adequately
> cooled by a Zalman passive. But depending on the chipset now,
> some of them are in the 15-20W range. The fan on those may have
> been barely adequate.
>
> These are numbers for some Aavid heatsinks. This tells you, that
> adding a fan to the Zalman, improves thermal resistance by a
> factor of three.
>
> Length Width Height still with
> mm mm mm air fan
> theta 200LFM
>
> 35x35 374624B60024 35.00 35.00 10.00 23.40 7.55 Black anodize
> 35x35 374724B60024 35.00 35.00 18.00 15.30 5.15 Black anodize
> 35x35 374824B60024 35.00 35.00 25.00 12.00 4.27 Black anodize
>
> This one has a theta_R of 1.25C/W. It has a fan.
>
> http://www.swiftnets.com/products/mcx159-CU.asp
>
> 35C + 1.25C/W * 15W = 54C
>
> 35C + 12.0C/W * 15W = 215C
>
> 35C + 4.27C/W * 15W = 99C (close to the limit)
>
> Ideally, you'd want a working temperature readout, so you can determine
> how well the new solution is working. Waiting for the system to crash,
> isn't a very accurate indication of what temp you're at.


I have a digital temperature probe, but its max. of 50 degrees F was too
low for the heatsink temp after the machine had been running for a few
hours. At least it hasn't rebooted yet. This Zalman heatsink is designed
for NB chips and has been recommended by many.

Perce

Isopropyl is fine .. the arctic silver cleaner is good too - alcohol is
cheaper - both do the job. For a CPU I use all three .. for a NB fan - I
would think the Isopropyl would be fine.

I just replaced my A8N-E for another MB on one of my computers. The MB was
suffering from the NB fan failing yet again ... also would have intermittent
reboots. I changed the RAM, PSU, Video card and still random reboots .. it
would lock up in the bios screen at times too .. I just replaced the board
with a new 785G board. I did keep the A8N-E though just in case I need a MB
desperately.



"Percival P. Cassidy" <> wrote in message
news:ha14s5$mks$...
> The original chipset fan on my A8N-E failed when the mobo was still in
> warranty and Asus sent a replacement fan free. Now the replacement has
> failed after only a year or so, and I bought a Zalman Northbridge heatsink
> to replace it.
>
> My question is: what should I use to remove the old gunk from the chipset
> before installing the heatsink (which came with a tube of thermal grease)?
>
> Perce