[SOLVED] Is this cooler still healthy?

Feb 25, 2021
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I bought a secondhand Asus ROG G20CB recently, only to find it has (can you guess?) cooling problems. The CPU cooler consists of a heat transfer plate connected to the fan-cooled fins via two (I believe) copper tubes. I have no experience of this particular model, but those tubes seem to have been crimped at the point where the enter the fins. This may have impeded heat transfer, but rather than rush out and buy a replacement, I thought I'd ask here. Looking at the pic, can anyone here say whether this is normal for this model of cooler? TIA ...


G7https://postimg.cc/hJ514Rfb
 
Solution
Basically a large laptop cooler crammed in a small form factor computer, not sure what you are expecting.

Those are called heatpipes, and they are not empty. They consist of a copper tube and typically a sintered (heat fused) copper powder interior volume, a small drop of distilled water is added and the tube sealed. The water evaporates under heat and the sintered copper gives it a place to re-condense creating a very efficient heat transfer. Very common in pretty much every moderately decent heatsink.

Any crimping like that is intentional, and it is quite common for them to be flattened in that manner for space savings or manufacturing purposes (in this case to solder/force the fins on). Best if they didn't, but that is what happens...

Eximo

Titan
Ambassador
Basically a large laptop cooler crammed in a small form factor computer, not sure what you are expecting.

Those are called heatpipes, and they are not empty. They consist of a copper tube and typically a sintered (heat fused) copper powder interior volume, a small drop of distilled water is added and the tube sealed. The water evaporates under heat and the sintered copper gives it a place to re-condense creating a very efficient heat transfer. Very common in pretty much every moderately decent heatsink.

Any crimping like that is intentional, and it is quite common for them to be flattened in that manner for space savings or manufacturing purposes (in this case to solder/force the fins on). Best if they didn't, but that is what happens inside of small spaces.

A quick google image search reveals this design in some detail.

https://rog.asus.com/forum/attachment.php?attachmentid=59786&d=1476543065&thumb=1

https://rog.asus.com/forum/attachment.php?attachmentid=59788&d=1476543239&thumb=1
 
Solution
Feb 25, 2021
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Yes. In fact it was after I'd done this and was trying to install Linux that I noticed a large drop of dirty water being exuded from the join between pipe and fins. Needless to say, I turned the machine off and posted here.
 

rubix_1011

Contributing Writer
Moderator
I would be curious as to where this water came from and whether it is the result of trying to remove a mounted cooler like this and the heatpipes getting bent or cracked. If so, the cooler is no longer able to be used.

Would need close up of where the drop is seen, assuming the liquid is being expelled at a fracture point or you have something else going on, like a spilled drink.
 
I have sometimes seen low end thermal pastes leave behind what appears to be water. Not sure if they separate over time or what, but I have seen this at least once. The last time I recall seeing this was on an FX8350 PC that was experiencing a lot of throttling. The paste was probably 8 years old and this had happened.

I would suspect this is the case here but I am not sure.
 
Yes. In fact it was after I'd done this and was trying to install Linux that I noticed a large drop of dirty water being exuded from the join between pipe and fins. Needless to say, I turned the machine off and posted here.

As far as I know, the fluid in heatpipes on coolers for PCs usually evaporates instantly when / if a heatpipe somehow breaks (it is only a tiny amount of fluid in each pipe as well), so I would be surprised if the liquid you are seeing, is coming from a leaking heatpipe.
I have cut open a couple of heatpipes with a dremel tool on a leftover Arctic Cooling Accelero Extreme IV cooler I had (out of curiosity), no liquid is coming from the heatpipe when they are cut open.

EDIT:

It was discussed in another thread on this forum, but I have been unable to find the old post about it.
 
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Feb 25, 2021
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Informative video. It would appear that the liquid I saw did not come from the interior of the cooler - there was simply too much of it. As I said before, I've just bought the machine, so I really don't know its history.