My PC has had a number of problems recently. It stopped powering on at all and, then starting boot looping. I took it to a repair shop and we found out that the CPU cooler was shorting the motherboard as the circuitry around the CPU mounts had been exposed from the mounting system wearing away the coating. All well and good, the guy at the tech shop put some insulating washers under the mounting nuts and it started booting fine. Took it home, tried to play some games and now I am having GPU issues. In game, my clock speeds are fluctuating between the normal pace of about 1300mhz down to as low as 650 before jumping back up. The memory clock, voltage and power consumption are all doing the same pattern. This cycle repeats itself every 9 seconds or so (attached image). At the time I captured the image below I was running PUBG sitting in the main menu (which usually puts a bit of stress on the system). I don't really want to take it back to the shop because the guy there is pretty expensive and he left fingerprints of thermal paste on my motherboard. I've got no idea what would be causing this. I've set the power settings to maximum performance in the Nvidia control panel, I've checked all the power connectors, I've re-seated the GPU. I am lost.
SPECS:
i7 4790k @ 4Ghz
16GB of Kingston HyperX Fury 1833Mhz
MSI-Z97 Guard Pro motherboard
Coolermaster G750M PSU
Coolermaster Hyper 212x CPU cooler
Gigabyte G1 Gaming 980ti