I'm trying to use an ATX power supply outside of a computer for 5V and 12V, but I can't get it to stay on.  Only, the purple standby wire is always at 5V.  If I ground the green wire the P/S will come on for a second and then go off.  I tried putting a power resistor between the 5V red wire and ground to create a load, but it did not help.  I also tried connecting the brown sense wire to the orange 3.3V, but that also did nothing.  Any suggestions?