Adreankael

It's a faulty reading. Due to a quirk of how temps are measured for the fx cpus, low idle loads / temps are inaccurate. I think the justification was that it was still accurate enough at load and that's what mattered. As long as your load temps are fine, there's no need to worry. 

Is your GPU sagging on the PCIE slot?  If so get it propped up and see if the issue goes away.  The power delivery pins are on the closest to the IO of the motherboard - I had a similarly described issue when putting GPU under load and after propping up my R9 Fury so it wasn't pulling down so hard on the PCIE slot, issue completely went away.

A couple of things you can try if you haven't already:
If you are using a surge protector, PDU, or UPS try plugging your PSU directly into your wall outlet for testing. Clear CMOS on your motherboard Unplug your PSU Remove the battery from your motherboard press the power button on your case 10-15 times to clear any remaining power from your board put your battery back into your board and test it It sounds like your PSU is the most likely culprit, if money is tight go to a local computer shop. They'll have a pile of PSU's to chose from usually 10-15 bucks. If that doesn't work they may even have a board that will work for you. If not check craigslist or a similar market place.

https://linustechtips.com/main/topic/1116640-psu-tier-list-40-rev-202/