I'm trying to re-purpose an old Compaq (and another HP) ATX computer power supply to use as a lab PS. I've seen tons of articles on line about how to do this, for example. I can't get it to even start up though. I have the power-on pin from the ATX connector that goes to the motherboard shorted to a ground wire, and have tried various loads ranging from 10 ohm power resistors to just plugging in an old CD drive to one of the molex connectors. Does anyone have an idea of what I might be missing?