Either the Mobo was bad when you bought it, or In the process of assembling and disassembling you missed something not being plugged in or you might have shorted out the board. Either way, it's a hardware issue that the board needs to be replaced.got a replacement motherboard. Installed it. At first when I tried to boot I got 7 error beeps which meant the cpu was not seated. I took it apart, check everything out ... put it back together again. This time nothing. Just the led light for the battery... a guess the beeps were telling me the motherboard it bad. It is the only thing that would explain why I have no power. .