I built a brand new rig, powered it up.and everything worked, installed Windows to my pc and everything was working fine. I then took my pc to my room, plugged it into an extension lead and everything lit up in my pc, I press the power button then it made a pop noise and the electrics went off. After inspection I found the fuse in the plug had gone, and a capacitor inside the psu had exploded leaving white remains over the inside of the psu. I checked the plugs ect, they were all working fine. The psu is an rm850. Has this damaged my rig? And why did this happen?