I was using my computer fine about 3 weeks ago, I shut the computer down and then when away for 3 weeks. I've just returned home to find out it won't turn on. The motherboard light does not even illuminate. The computer had not been touched for 3 weeks and was on a surge protector, I'm automatically assuming its the power supply.( Corsair HX850 ) But wanted to wait and see what others thought? I'm also curious if it is the power supply, how could it die while not being used?