Computer Wont post

[ReconSniper]

My friends computer powers on, then after a few seconds of fans spinning ect it shuts off. Nothing ever shows up on the display and no beeps. He bought a new motherboard thinking that was it. It does the same thing. He has unplugged everything from the psu and mobo. So basically the PSU is hooked to the mobo and thats it. Still nothing. He tried an OLD MObo and it works. Could it be that both his old board and the one he just bought are bad? is there something else missing here?

 

[rodsfree]

Has he tried a different PSU.
The old board might have lower power requirements that allow it to work with his PSU.
Then the new board(s) are trying to pull too much juice from the PSU and not getting it.
It's happened to me before.