The computer was working. I wanted to swap out parts to test anothor computer. I put the identical mother board in and It would not power on, completely unresponsive. I put this motherboard back in the other computer and it functioned as before, stupid, but powering on. on the previously working computer I dropped the CPU on the floor. I put the origional working motherboard back in. I put the CPU in ( I later put the CPU from the other computer in) I still cannot get the board to power on. When I test the power supply the fans and drives power up, but when connected to the motherboard absolutely nothing happens.