[SOLVED] GPU old thermal paste won't come off

[mrtech9]

I have an old R9 390 Gigabyte card that is known for high temps & bad fans. I bought this used card 3 years ago and it works fine, but it always had this burned stuck thermal paste that I cannot wipe off. Also, after every 2 months I need to change thermal paste since it dries up really quickly & high temps return.
Does anyone know how can I clean this properly? I used an alcohol, not sure if its isopropyl, but it does nothing.

 

[Darkbreeze]

Use (ONLY) "91% Isopropyl alcohol" for cleaning thermal interface material off PC parts, except for where CPU and GPU specific cleaning solutions have been purchased. Even so, I'd never buy one of those solutions because I've never found anything that works as well or is as safe to use as 91% isopropyl alcohol which is relative cheap (Again, after it got very expensive during Covid) and widely available.

If it will not come off using a lint free cloth or paper coffee filter and 91% Iso alcohol, then you can try lightly lapping the surface of the heatsink and GPU using very fine (2000-4000 grit) wet-dry sandpaper with a small block or piece of glass that is completely flat. There are plenty of guides to lapping surfaces like these online and while the purpose here is not the same as for when lapping is normally desired, it may work to remove some or all of that burn in you see on your parts. Also, if you are using a lower concentration of alcohol like 70%, be aware, that doesn't work worth a crap on thermal interface material since it is 30% water and highly diluted. 91% Iso alcohol has just enough water in it to ensure it does not INSTANTLY evaporate, but will still cut through most thermal interface materials (Paste, remnants of thermal pads, etc.) while also evaporating quickly enough to not pose any risk to any of your hardware due to still being present later when the device is powered back on or your parts are assembled trapping fluid.

I'd also recommend that you get a can of compressed air and some Q-tips, and slowly make an effort to remove that additional TIM you see around all the small bits that are around the outside area of the GPU itself. All those little resistors and other components. That old paste should absolutely be removed prior to applying new paste. After cleaning, use the compressed air to help remove any remaining small hairs from the Q-tips and from the probably left over tiny "sand" from the sandpaper that might be there from the lapping that didn't get removed in your final wipe down with alcohol.