My computer was running one day after I re-built it a few weeks prior to this, and when I got back to it, It had shut off and wouldn't restart. I changed the power supply and tested the CPU so both are good. I tried anouther HDD in it that I knew worked and still no change. When I power the computer on, everything starts to work but nothing is displayed on the screen yet when it just shuts down. The power switch doesn't work at all but, the reset switch will power it on after pressing it twice in a row, after each shut down. I switched to a case that I used to use for the same system and still no change so I know the power switch isn't plugged in backwards. The case I was using when the problem occured was a case that housed another system, but the mother board went in that system. the only part that was not swaped out of the old one was the case, the cd drives and the floppy drive. Is there a such thing as a case killing a mother board.