Strange liquid on damaged GTX1080 card

[kurland]

Hi,

I'm fixing a GPU card for a streamer, was sent to me by mail. A shorted cap on a power rail has severely burned the PCB.



As you can see from the darkened PCB around the mosfets there are signs of liquid damage. But it's odd because the person says no water has entered the PC cabinet. If you spill something on a desktop you would know I guess...

Funny thing is that the liquid is not only on the PCB but on top of many chips which are tightly covered by thermal padding under the heatsink, even on top of some of the RAM chips



In photo below, to the left are mosfet drivers with obvious liquid on top. Notice also the chip to the right, the PCB is darkened by liquid/heat just around it ...


The liquid is not water because it's not drying up, and it has also darkened areas of the PCB.

First my theory was a cap with leak, but that's not the case, no signs of leaky caps.

I figured it can be coolant from the liquid cooler in the PC. But the distribution pattern doesn' make sense, besides the mosfet area there are sporadic liquid across the board wherever thermal pads cover chips. Also, this side of the card is oriented downwards when situated in PCIe slot, so kind a hard to get liquid distributed like this.

It's almost like the liquid comes from the thermal pads themselves..? But I have never heard of that...

Any thoughts?

[gabiz_ro]

Re: Strange liquid on damaged GTX1080 card

I saw in some cases something oily on some thermal pads,In some TV or other devices.
Mostly on thicker ones thermal pads.

[diif]

Re: Strange liquid on damaged GTX1080 card

I've encountered that oily liquid under thermal pads.

[kurland]

Re: Strange liquid on damaged GTX1080 card

Thanks for feedback, it makes sens from what I see.
But could this really cause short circuits?

[kurland]

Re: Strange liquid on damaged GTX1080 card

Answering myself here,

It seems such oil sweating from thermal pads is common but should not cause a problem.

https://www.overclock.net/threads/vi...g-oil.1496615/

[piernov]

Re: Strange liquid on damaged GTX1080 card

Yeah looks like grease from the thermal pads. Shouldn't be conductive, clean it anyway and you'll probably have to replace the thermal pads as well (some of it got stuck on some chips so they're probably not in good shape).

The cap may have failed on its own. There's a chance it caused the PCB to burn, so clean the area, gently life the trace that's damaged and check if the PCB material is carbonized under it.

[silentbogo]

Re: Strange liquid on damaged GTX1080 card

It's not conductive, but it may cause slight issues.
Few years back I had a couple of cards in my workshop from one of my office neighbors, which started artifacting all of a sudden (HD7970 and GTX1080Ti). At first I thought it was either GPU or VRAM issue, but then I took off the heatsink and saw a flood of slimy thermal pad snot all over and under GDDR5 chips. Just a quick IPA bath, and some scrubbing fixed the issue on both cards.

But in your particular case, I doubt it caused that cap to die. Just a typical defective/cracked ceramic capacitor. I'd still clean the crap out of it, just in case.

[kurland]

Re: Strange liquid on damaged GTX1080 card

Unfortunately the board was not fixable. The PCB was completely carbonized half way through. Even after carving out a whole I was not able to get rid of the short. I checked all fets and caps remaining on board and they're ok, so I suspecte it's the GPU itself.