[SOLVED] Screen doesn't turn on when graphics card is plugged in

Jul 8, 2021
I've been having issues with my PC for a while, but I have no idea where it comes from... I'll describe the issue below, but first here's my setup (bought in january 2016):
  • i5 4690K
  • MSI Z97 Gaming 5
  • Radeon R9 380 Gaming 2G
  • HyperX Fury 2x4GB
  • Seasonic M12II-620 EVO 80PLUS Bronze
  • Samsung 850 PRO 128GB
  • Windows 10 Professional
Also, since I first suspected the GPU, and then the PSU, I tried to replace them with the following parts:
  • MSI GeForce GT 1030 Aero ITX 2GD4 OC (gets power through the PCI slot)
  • Seasonic FOCUS GX-650
However that didn't seem to change anything.

So anyway, here's a rundown of the issue (occured with both GPUs and PSUs):
  • When powering the PC, the graphics card lights up and its fans start spinning, however the screen doesn't turn on (it's connected to the graphics card). Nothing else out of the ordinary: the motherboard, CPU fan, and my keyboard all power up correctly.
  • If I connect the screen to the motherboard while the GPU is still plugged in, the screen does turn on (from sleep mode), but doesn't display anything (it stays black).
  • If I remove the GPU, the computer boots correctly and lets me access the BIOS (the iGPU takes over). In that situation the system looks rather stable.
  • When I change the boot order in the BIOS to use the iGPU first, the PC can boot even if a graphics card is plugged in. However the graphics card is not detected by the BIOS nor by Windows (PCI slot is displayed as empty). There was one time when I saw it appear, but after rebooting it wasn't there anymore...
  • If I plug in my Wifi card in the same slot as my graphics card, the BIOS doesn't detect it either.
  • Since I suspected that a PCIe slot might be dead, I tried the same manips using another one, but same things happened.
  • I tried clearing CMOS, but nothing changed.
Here's some other stuff that might (or not) be related:
  • Recently my sound card (connected through PCI as well) has been malfunctioning a bit: the audio cuts off in one ear when I rotate the jack connector around (headset is still pretty new).
  • Before my PC "died", I was already having some issues: in certain games, I got random crashes where the game freezed, the video crashed, but the audio and game engine were still running (I could hear myself walk in the background). The AMD drivers (Radeon Sofware) crashed as well, but my screen didn't actually turn black (only the game crashed).
  • It might be worth noting that according to CrystalDiskInfo, my SSD is perfectly healthy.
So yeah that's about it. I'm kinda bummed out, I really thought that getting a new GPU & PSU would solve the issue... I could buy a new motherboard and CPU, but if this doesn't fix anything I will start losing my mind... It could also be the RAM, but I don't see anything that points towards that being the issue.
Jul 8, 2021
Update: so after messing around even more, I noticed that if I switch the new graphics card to a different PCI slot, and connect the screen to it, everything works. Apparently I didn't try this before, which is a bit surprising.
This still means that both my old graphics card and a PCIe slot are dead (unless I'm missing something), but hey at least now I can play games again.