Never rule out the power supply. PSU problems are the worst. And especially high current systems like ThreadRipper.
Let me tell you about my power supply issue: System ran great for 4 weeks. Then I had one reboot, figured it might be software. Then it happened again, and again, increasing frequency. I had that sinking feeling in my gut, but I had all quality parts, and my build was meticulous (I’ve been building systems since the turbo XT days). After eliminating shit like USB devices as a culprit (USB is shit!), I suspected power.
Turns out the EVGA 850 P2 power supply was shit when in silent mode. I turned on the fan always mode (it’s a switch on the power supply) and things stayed up. I filed an RMA request with EVGA. I installed the replacement power supply, and it failed within an hour. It was worse than the original one.
So, I went and bought a Corsair RM850 power supply. Arguably, not as good as it’s only gold, and the EVGA PSU was Platinum. However once I installed the Corsair, everything has been great (100+ days uptime, never a single crash since). Fortunately, Amazon allowed me to return the original EVGA power supply and I shipped back the bad replacement EVGA power supply at their expense.
I’ll never use EVGA again. Not only were their power supplies crap, but the hoops they make customers jump through are absurd.