Computer shut down all of a sudden and doesn't boot anymore, only LEDs and Fans are working

pizzaisawesome

Prominent
Jun 29, 2017
2
0
510
My computer doesn't boot. I already tried the troubleshooting guide but it still does not work.
I built this PC myself and had no problems with it until recently, when it suddenly shut down a few seconds after i logged into windows. After booting back up without a problem and trying to start a game, an error occured, stating that the file is corrupted. Therefore i deleted the folder and downloaded the game again, which was successful but after i was playing for roughly 20 minutes, the computer automatically shut down.
It then immediately tried to restart by itself (fans spinning, LEDs on, etc) and shut down after a few seconds. This process repeated itself until i manually turned the computer off.

The EZ debug LED on the Mainboard is shining red. The GPU lighting's color is red, which indicates a heavy load on the GPU, even though there is nothing it has to do.
Afterwards, i went through the tomshardware troubleshooting guide without any success.

specs:
ROG matrix platinum gtx 980
i5 6600k
msi z170a pro
8gb ddr4 Kingston
corsair vengeance 550w

The mainboard LED obviously points towards CPU failure, but that doesn't really make sense to me as the PC was still working afterwards.. I got no idea what the problem might be though so i definitely appreciate any input.