I've been having this problem for 2 years now and after months of frustration I was finally able to narrow it down to a possible GPU issue.
Basically, when I play flashy games, sometimes my PC just... freezes and crashes, or crashes immediately. No error screen 9 times out of 10, the other time I get a SYSTEM_SERVICE_EXCEPTION blue screen. Sometimes the crash is accompanied by a loud noise (from the game) right before the PC restarts. This doesn't happen during every game though, but it sometimes happens with Overwatch and it happens with Borderlands 3 a lot, so much so I can't play co-op because sometimes the game crashes after only 5 minutes of playing. And sometimes, I can game for hours and it's all fine. I have no idea what could be causing the issue and I'm really desperate.
What's the weirdest thing is that.. it doesn't just happen while I game. I've had it happen sometimes while I just.. browsed the internet. When that happens, the PC freezes suddenly, the loud noise is there, and then it either crashes by itself of I have to manually restart it. Although this is rare.
One time, the crash made it so my PC wouldn't boot at ALL until I reseted CMOS.
AMD Ryzen 7 1700X
AMD Radeon Sapphire RX480 Nitro+ 8GB
32 GB RAM (2x Corsair 16GB KIT DDR4 3000MHz CL15 Vengeance LPX)
All drivers updated, Windows is updated too. This has been happening ever since I built this PC, pretty much. I just wanna know what's wrong with my PC.