cut yourself off some wire ... and strip both ends .... then look for the green wire (on the lead that connects to the mobo)
take that piece of wire you just prepared and stick one end up into the green wire socket .... now take the other end of that wire and stick it into the black wire (ground) socket right next to the green one.
if its a switched PSU ... just flip the switch and you should hear or feel the PSU fan kick on
if its not switched ... as so as you touch the ground wire the PSU will kick on
then you can check all your wires with a DMM to make sure the voltages are correct
Hope that helps ya out
