After building this rig, I've been experiencing a strange type of crash while the system is under load (specifically while gaming). After playing for a few hours, the screen would abruptly go black, no error message, and the RGB's on my GPU would go dark. Reset button is unresponsive, and the only way to reset is to shut off my PSU and start it up again. Specs below.
Mobo - GIGABYTE X470 Ultra Gaming
CPU - Ryzen 5 2600X
CPU Cooling - Stock CPU Fan Cooler
GPU - GIGABYTE GTX 1070 Ti
RAM - G.SKILL TridentZ (2x8gb)
Storage - FireCuda 1TB SSHD Hybrid
PSU - Okia ATX600 600W
I have not overclocked the CPU in any way, but at one point it had been run with a bad set of thermal paste. I knew the paste was bad, but didn't have the money to purchase a tube of paste at the time. I ran it with some games, checked the temps, and nothing went over the line of concern. Everything was staying cool, and now the paste is replaced properly. I have no idea what could be causing this problem.
Vermintide 2 is one of the games giving me the most problems. After running, when I select my character, before I can even click, my PC crashes. I've swapped my GPU and RAM to my brothers PC to test, and they both ran Vermintide 2 with ease, so it's not them. I've narrowed it down to being either my PSU, CPU, or my motherboard, and I want to know exactly what it is before I go making purchases. Thank you for your help!