Started having issues with my PC randomly rebooting while watching movies or playing games a few days ago. Swapped out the EVGA 750 P2 with an unbranded 800W PS that I had sitting around and that fixed the issue.
Using the power tester the 750 P2 comes with, I was able to verify the unit turns on and all rail voltages were checked and are spot on. I reconnected the EVGA PS, but left the unit outside of my case and ran some benchmarks to stress my system. Sure enough, after a few minutes the system would just reboot. The fan is turning on and spinning, but the fan does not seem to be moving any airflow through the unit and the speed of the fan never seems to change or ramp up as I actively monitored the fan speed as I was running the benchmarks when my system would randomly reboot.
Eco mode was off during this testing, but even turning Eco mode 'ON' had no effect on the fan speed as I've read it should in other posts here. At the time this started to occur, my ambient room temp hovered between 68-74F as I have my thermostat set to 72F. So I kicked on the AC and brought the room temp down to 64F and the issue did not occur after several hours. Set the thermostat back to 72F, and after the room temp equalized my system would once again shut down.
Anything else I could check, or does it sound like RMA time?