Cyberpowerpc gma6600wst restarting when gaming/streaming

[trentklein]

A friend of mine streams on twitch and has been having random pc restarts while doing so. I walked him through testing each ram stick first, which they all seemed fine. Next had him reapply thermal paste and that worked BUT then after some time, it started to do it again. Meanwhile his cpu (ryzen 7 3700x), which is not overclocked, has never overheated. After some more digging we decided to replace the Apevia psu that came with the pc but which again seemed to work, but still is having the same issue. He lives a few hours away so I want to help him the best I can without having him buy all these replacement parts. I know it could literally be anything, but does anyone have a solid solution? Thanks in advanced!