Question Overheating on a used 1080Ti AORUS Xtreme ?

Dec 16, 2020
So long story short I've bought an used 1080 ti aorus xtreme to complete my build but when I installed it and tried it I probably got overheating problems which freeze the PC. I've made a Reddit post where I explained the problem a little bit more and two people told me that it's probably cause of dried out thermal paste which is what I thought.

Because I don't really feel comfortable disassembling I went to my local pc store to ask them about it. After I've explained him my issue with the gpu he told me that it's probably not the thermal paste etc. and that changing it would probably not help that much cause the 1080Ti isn't that old to have dried up paste. He told me that the gpu board or the chip are probably faulty.

Is that possible when the fans on the gpu are working and the gpu has expected performance? If you need more info about the problem or my setup just let me know and I'll provide them asap.
Also I'm sorry for any grammatical errors I'm not native English speaker.