Question Radeon R9 280X disappeared all of a sudden...

[Salem Nikolaevich]

Hello all, I'm re-posting my issue because the previous one hit a dead track. I'm experiencing the most weird problem I've ever had with a PC...
As title says, my GPU is completely disappeared from my PC. Not showing in device manager (not even under hidden devices) nor is recognized by any means by the PC. Initially I thought the GPU has simply failed and that's that, but after doing some researches, I found some options:
Reinstall windows: Did that 3 times, not working.
Change the motherboard: My previous MB had this weird graphic glitching problem while using the integral HDMI slot, so I thought that maybe was linked to it, but even after changing it the problem persists (the Glitching is not appearing anymore while browsing or else)
Now, when I manage to make it work, it works like a charm, I can play games (even something like MW2019 that is pretty heavy for this GPU) I can watch movies, videos and all for hours and has no problems, no freezes, glitches, errors, crashes nothing. When I put the PC to sleep or shut it down the GPU disappears...The fans starts up, the Vapor-X logo turns on but the green LED strip that shows the device is working doesn't light up and the GPU is not transmitting anything and I have to use the Vega 8 of the CPU. Other than this weird graphic issue, the PC has no other problems. I tried with all kind of drivers, updates but nothing works. I hope to find some help here. Thanks in advance.
UPDATE: I've managed to reinstall the GPU this afternoon, but after the PC was off for a couple of hours, it disappeared again and appears as hidden device in Device Manager...
PC Specs:
CPU: AMD Ryzen 3 2200G with Radeon Vega Graphics
SSD: Samsung SSD 980 1TB (Brand new, installed today)
MB: MSI B450 Tomahawk Max II
GPU: AMD Radeon Vega8 Graphics (Current), AMD Radeon R9 280X Vapor-X (The non-working)
RAM: Two G-Skill Ripjaws V DDR4 for a total of 16gb RAM.

 

[Eximo]

Well, when having odd problems it is best to go to the roots of things.

1. Check your power supply and particularly the wiring to the GPU (Confirm 12V stays above 11.4V even under a load)
2. Verify the motherboard and chassis are properly aligned, this can make a GPU's connection intermittent.
3. If your GPU is showing excessive sag or bending, it may be worthwhile to re-do the thermal paste and re-install the card
4. Update the BIOS on the motherboard
5. Update the vBIOS on the graphics card

I would normally also say re-insert the CPU, but the motherboard swap should have done that for you.

It is possible the CPU is the problem as well, but that would be a last resort. Nothing worse than an intermittent CPU to troubleshoot. (Reasoning would be the PCIe lanes going to the graphics slot could be the problem)

 

[Salem Nikolaevich]

I made all these checks already, plus scan for broken registry editors and updated the Visual C++...In this very moment, the GPU is connected (after being physically connected to the MB but not powered all day) and I've just played 2 hours of CoD MW2019....I used the PC in the early morning without the GPU, I came back for lunch, I plugged in the GPU and it worked then I powered off the PC for no longer than a hour and a half and after powering up it was gone again...3 hours ago I plugged it back in and now it works...Seems that after power off/Sleep, It goes into a stasis, the few hours later, it comes back to life...I had experience with faulty CPU and the whole PC starts to run bad, with freezes, crashes, BSOD, slowing down and I have none of these problems...Not even when playing any game, heavy or not...

 

[Salem Nikolaevich]

UPDATE: AMD software (And drivers) acts weird: Drivers won't install (Says no compatible device detected) and AMD software sometimes works and sometimes won't...Seems like it keeps downgrading itself since when I try to open it sometimes says that the wrong version is installed. I tried to go back to a previous windows version but Failed to accomplish anything save for some programs were uninstalled and now Windows version 20H2 keeps failing to update...Yesterday night the GPU worked like a charm (I played MW2019 for like 3 to 4 hours and worked flawlessly) save for the fact that when I enter the game says the wrong version of AMD driver is installed (says I'm using 16. something, but I have installed the latest 22.5.1)... I'm getting crazy, I don't F*** know what the hell is going on RN...