Electrical sounding snap/Crack then PC shutdown, turning it on now only turns on lights and fans.

Last night there was a electrical pop or Crack sound before the PC shut-off completely. Turning it back on there's no longer a display and keyboard, mouse dont come on. The fans and lights inside seem to be all that actually activates.

The psu is a gp-650 bronze 80 plus from game max and looking around they seem to be unreliable as a company/psu, so I assume thats the issue but no clue otherwise.