Quandary for the brilliant folks here: what would cause a GPU to only work in Windows Safe Mode, or when using generic VGA drivers?

I bought a GTX 285 off eBay for cheap. I figured I could experiment with it in my WinXP machine ( Z68 mboard, i7-2600K CPU ) to see how it did with older games vs the 750 Ti that was already in there. So I uninstall the drivers, pull the 750, install the 285. The machine boots up normally and goes into default VGA mode. I go to install the 340.52 drivers. Halfway through installation the screen goes blank and stays that way, machine is completely unresponsive. A few forced reboots and it doesn't change. I install the 285 in a completely different system ( B660 motherboard running Win10 that I'm much more willing to sacrifice if the GPU decides to torch the slot ). This one I don't get any display at all, not even POST. I guess the 285 isn't UEFI compatible?

I pull the 285 out, remove the cooling shroud, and give it a thorough inspection. It's not in the best condition. Dust bunnies everywhere, thermal paste caked on the die, some rust on the inside shielding of the DVI ports, even some corrosion on the aluminum cooling fins. I clean and dust the board, clean off the die and cooler plate, apply new paste, and re-seat the thermal pads on the memory chips and other parts. Despite the not great condition, I can't see any obvious physical damage like a cracked PCB, loose components, or missing pieces.

I try again in the WinXP machine. Still a blank screen, this time I don't even get a POST. I install the 750 Ti back in. The machine boots normally. I shut down and switch to an 8300 GS. Normal boot there too, so it's not a problem with the PCIe slot. Then I swap in a 1070, thinking maybe my PSU is having troubles with the 285. But the 1070 works fine too, so if my PSU can power a 1070, there's no reason it should struggle with a 285 ( it's a be quiet! Straight Power 10 with a single 40A 12V rail ). I try using different DVI ports on the 285 and different DVI cables, both single- and dual-link. Nothing gets the 285 working in the WinXP build. All those changes are reflected when using the other GPUs, like the dual-link allowing 2560x1080 resolution.

Then I whip up a quick bench system with an X99 board and different SeaSonic 620W PSU. No integrated graphics to cause weird setting conflicts. I turn it on and I get a display. I can get into UEFI/BIOS and change settings normally. So I follow with a quick Win7 Home 64 install (no XP drivers for X99, and the Z69 is the oldest PCIe mboard I have ). Everything works as expected, display is up the entire time during installation. Go through initial setup, make a user, no problem. But before I get to a desktop, screen goes blank. I see a corrupted BSOD error screen but can't read it. Machine reboots and it looks normal. POST screen, starting Windows animated splash screen, even the blue loading screen right before the desktop are all displayed just fine. But the instant the normal desktop would be shown, the screen goes black and then eventually the machine reboots. It's like it can't load explorer.exe or something.

After that reboot, it gives me the recovery options, so In load into Safe Mode. Everything works just fine here. I get to the desktop, I can launch programs, view the device manager, everything. Under device manager, the display adapter isn't listed as a generic VGA device, it's specifically a GTX 285, thought using a MS supplied WDDM. I reboot from Safe Mode and the same problem occurs again. All screens up to the blue "Loading" screen show fine, but it again goes to a blank screen before ever showing the desktop.

I swap out the 285 with the 8300 GS. Booting is totally normal and I get to the desktop. The device manager against shows a 8300 GS using MS WDDM. I install the 342.01 drivers, as they support both 8300 and 285 cards, reboot, and of course the 8300 in device manager no longer shows the generic MS WDDM. I shut down, re-install the 285, and boot into Safe Mode. In device manager, I update the 285 driver and let the machine search for one. It of course finds the info from the 342.01 drivers and updates the generic driver to the Nvidia specific one. I reboot and try to start Windows normally. This time, the blue loading screen doesn't show. After the animated Windows 7 splash screen, the display goes blank and I get the normal reboot.

So, if you're still with me after all this, I'm not sure what else I can do. To sum it all up, the exact same behavior is happening in both WinXP 32 and Win7 64, so it doesn't look like it's an OS specific thing. It works in both a Z68 and X99 board, so it doesn't look like it's a platform specific thing, unless it's with all Intel platforms. I've used other GPUs in those boards in the same slot, so it's not like the PCIe slots are damaged. I've used it with two different PSUs, two different monitors, both of which were different native resolutions, and two different DVI cables.

With the state the GPU was in when I got it, with rust and corrosion, there's certainly a decent chance something on it is damaged and the thing is just scrap. However, the card otherwise works fine when it's using generic VGA drivers or is in Safe Mode. I can leave Safe Mode on for a long time and nothing weird happens. The board gets hot, cooler is on, but I don't see any flickering or screen artifacts, so at least on a basic level the card seems to be perfectly functioning. However, the instant it uses any kind of drivers specifically for the card, it won't work at all, and I'm not sure why that should be. Maybe with the drivers on, special logic and other functions are called that otherwise are completely dormant with generic drivers and it's in those areas where the GPU is damaged. Or maybe the GPU BIOS/firmware is corrupted?

Has anyone seen anything like this before?