Originally Posted by H4x3r
the powersupply itself has to be switched on, first there is a switch on the back of the PSU..and secondly it has to be told to "turn on" by the mobo, that is usually done by hooking it into it's 20+4 pin power connector..and pressing the button on the case, or in some cases can be done with a jumper....either way it has to be told to switch on
Exactly this. it won't just simply turn on it has to be 'shorted' by either the jumpers on the MB or the power button on a case.
You could connect it to your motherboard then short the two power pins yourself with a screw driver if you want.