One thing that I noticed on my GPU. The fan wasn't cycling up whenever it was under load. So instead of going up from 40% of air, it stayed at that level, which always led to the GPU getting up 60 degrees Celsius, and inevitably shutting the PC down. I have to manually set the fan to increase to 60% of fan speed, and that brings the GPU temp down to 50 degrees or lower. Still looking at this, trying to understand why its acting like that for me, but it's something that could be affecting you.