Issues while playing games

[minolaft]

A couple weeks back I downloaded fallout 4, and its been a nightmare since then. Every time I try to play something my computer screen goes black and the audio from the just crashes and becomes very loud for about 10 seconds and stops. I can still hear my computer running but no audio or visuals at all. This has mainly been happening in R6S and fallout 4. Ive had enough of this, thus posting on this site for answers. This issue mainly happens around 30 minutes of gameplay
Ive done a full format of my hard drive and reinstalled all of my drivers but still nothing. Ive checked for temperatures on gpu and they are about 50c° and climb to about 100c° while in game. I havent checked cpu but I doubt it would be an issue here. I havent reinstalled fallout since the format but the issue remains.
GPU: AMD Radeon HD 7800 series
CPU: AMD FX(tm) 4100 quad core processor
RAM: 16gb
Psu: 500w
Edit: I switched on my computer today and it froze on the windows 10 loading logo, it doesnt seem like a games only issue anymore.

 

[RememberThe5th]

I think the 100*C is the TJ max and GPU cuts out to perserve itself, well only resonable would be to clean it up/dust it, apply new thermal paste and thermal pads if necessary.
There are a lot of guides on youtube how to clean up the GPU.
The problem is that you cannot test your rig without the GPU as it doesnt have intergrated graphics. Well if you can borrow or buy dirt cheap like GT 210 and test out (if this option is possible).

And before doing all of this when did you recently cleaned up the PC?