Question GTX 760 inherited from friend not working

[foxhound525]

So I build a PC for a friend many years ago, and it developed a fault of some kind. The guy didn't have any urge to do anything about it and live I far away so his system has been gathering dust for the last few years. I suspected the GPU is problematic and he finally brought his old GPU so I could test it. FYI the problem used to be that during some particular games his display would go white with black boxes.

So I have his 760 now, swapped it out for the 560ti sitting in my old system;
FX 8370 overclocked to 4.7ghz
2x 8GB 1600 mhz DDR3
SSD & mechanical drives
650W PSU

Ran geforce experience , it fetched the drivers... and then weirdness kicked in. After installing the drivers, the button to install the drivers was still present. So I did it again... still no change. That was weird. Ran heaven benchmark 4.0, it said something like hardware shadows not supported and closed itself. I could and did run that on my 560ti so that made no sense. Went into safe mode, ran DDU, manually installed the right driver after via the nvidia website, re-ran heaven... same story. Checked GPU-z, it cant read anything from sensors. It can see the card, just absolutely nothing being reported, same with afterburner. Ran killing floor 2, not playable at all wtth single digit FPS (it was better on my old card). Check device manager and it says windows has stopped the device due to a reported problem. Tried removing the device ,and repeating many of the things above, same old message.

What confuses me is that it still gives display, It's still usable for anything but gaming at 1080p, so it isnt dead. Fans are spinning, reseated it... I really don't know what to make of it, but I can't get it to work for its intended purpose.
Does anyone have any advice or expertise here? Is it a write-off?

 

[Sick Jacken]

Does the card sit properly into the slot, I say because if it sinked for like 90 but that last left side small part not the one where it clips stays a bit outside, it can still get detected and undetected at same time. I dunno, I think NVIDIA driver support is far better than AMD because nvidia, the low budgest card you can get from'em is either gt 730 or gtx 1660 some, pretty cheap. So if you had AMD gpu maybe but in your case isn't the GPU, i can put my hand in fire, if the GPU had problems first of all it wouldn't boot try maybe see if any thermal paste leaked onto the rest of the chip, yep it happend to me back when i had my gtx 980, a bit leaked on those small shiny things which are chips and the gpu doesn't like that, if not try without SSD, see if in virtualization machine mode works. SSD's are shady af, that's why I don't buy.. those firmware updates

 

[foxhound525]

Does the card sit properly into the slot, I say because if it sinked for like 90 but that last left side small part not the one where it clips stays a bit outside, it can still get detected and undetected at same time. I dunno, I think NVIDIA driver support is far better than AMD because nvidia, the low budgest card you can get from'em is either gt 730 or gtx 1660 some, pretty cheap. So if you had AMD gpu maybe but in your case isn't the GPU, i can put my hand in fire, if the GPU had problems first of all it wouldn't boot try maybe see if any thermal paste leaked onto the rest of the chip, yep it happend to me back when i had my gtx 980, a bit leaked on those small shiny things which are chips and the gpu doesn't like that, if not try without SSD, see if in virtualization machine mode works. SSD's are shady af, that's why I don't buy.. those firmware updates

It does fit properly in the slot, I tried to reseat it a couple of times just to be sure.

He hasn't made any after-market modifications like repasting or whatever.

Not sure I understand what you're saying about SSDs?