My PC's a gaming rig and occasially used for Mining, at some point my 620W Cooler Master Silent Pro M2 could not put out more than ~220W and I put my hand on the Power Supply, my hand where almost fried as it was so damn hot, I let it cool down for a few hours and then stress testing my 2 videocards but even at stock my PC crashed and at that time it was pulling ~280W and the Power supply was so hot again and so vague smell of burned plastic began to fill my room, i''ve had this happen everytime i was mining but now I knew it was from the power supply and today I unscrewed the thing and pulled it out:
I almost had to cry, my case had the Power supply in the bottom, and with all normal cases, there is a fan-cutout in the base of the case, my Antec 900 appeantly doesn't have this and the idiot who put my PC together put the fan pointed down, so it could not get any air.
I turned it over and now if my whole system is stressing it pulls 450~ Watts without a problem and the Power supply stays fucking cold -__-
That could of had fryed my PC.
Should send a complaint to who put your system together, that could have cost you a good chunk of change.