PSU or motherboard faulty?

[Balinus]

Hello,

I have a problem with either my MB or my PSU. Before returning both, I'd prefer if I could just return the faulty hardware. I made a short video of the behavior so if any one can help me, that would be greatly appreciated!

http://www.youtube.com/watch?v=X3xGyjvlKYs

Sorry for the english

To sum it up :

As soon as I plug the PSU into the wall, the fans and the HDD begins spinning.... Then I turn on the PC and the PC behave as normal.

When I just plug the ATX 24pin power, only the fan are spinning (no power to HDD). But when I connect the cable on the ATX power (so that SATA cable etc have power), the HDD is beginning to spin.

I don't have a lot of experience building PC (last one was a 386!), but I can understand

Thanks a lot for your help!

MB : Asrock A75M-ITX
PSU : 120W picoPSU

 

[kbp]

do you have the power button plugged into the correct pins on the motherboard....and the reset button plugged into the motherboard correctly???

 

[Balinus]

I don't have a reset button.

I believe that I've adequately connected the power button. It is plugged as shown in the figure below. The positive is in PWRBTN# and negative in GND.