Compaq with no power

[Hodsocks]

I have a Compaq Praesario 5000 with what seems to be no power to the 12V circuit. When I power it up the power light illuminates, the PSU fan spins, as does the cpu fan but none of the 12 V items seem to power up, no DVD, Cd-Writer . floppy or hard drive, There is no signal to the monitor either,
I have changed the PSU but it made no difference, which leads me to the conclusion that it may be the motherboard, although it seems to be selective in the circuits selected. I have changed the BIOS battery just incase it was something strange like that.
Have any of you guys any further suggestions, are there any problems with changing a motherboard on a compaq? On the face of it it just seems like a normal micro ATX board.

 

[poertner_1274]

That is a strange problem, are you sure it isn't your outlet? I know this sounds strange, but I had an outlet in my house that was negatively hooked up, meaning the hot was on the wrong side, and it messed up my comp. This might be something to look into.
But if you haven't had these problems before, then I don't know what to tell you.

 

[Hodsocks]

The power lead and supply I used were from another computer in the same room which had been plugged into this supply socket so that is not the problem.