I'm trying to use a small ATX power supply (version 1.0 connector) as a bench power supply. I've found that it only turns on intermittently. I've tried with ~1A load on +5V, and 0.2A on +3.3V .
I accidentally shorted +5VSB to ground, and it turned on. Now I find I can reliably turn the power supply on by momentarily attaching a load to +5VSB, maybe about 0.2A.
Is it possible that this PSU needs a load on +5VSB to start up (but not to keep it running)? An "ATX Design Guide" online lists only 0.0 amps as min current on +5VSB. Is it more likely that the PSU is damaged?