Changed son's innards over to new case. My old one and it worked fine for me.
Same PSU from his old case, same everything. I did take the CPU off, remove old paste and reapply some Arctic Silver 5.
Anyway, when I turn it on, it powers on then resets about 5 seconds later. No video output at all, no beeps. Checked behind board for something causing it to short, nothing. Did a barebones startup, no difference. Tried unplugging the power switch from the board, no difference. In desperation I unplugged every front panel wire from the board!
Any help guys?
EDIT: forget it, I took the CPU off and reinserted it as ell as shook the case all over the place and banged it against the floor several times in case I mi8ssed something that was lodged on/between the mobo. I broke off the USB flap cover, but it works. :s