ORIGINAL: rash_powder
<snip>.......My supply will not activate unless I disconnect a five wire connector from the little board that says it is for the fan control. I do not know if this harness is important. I still get heat from my power resistors without it (2 10 ohm in parallel), and about 12.15v off the 12 volt rails. Am I gonna cook something without it? It just does not seem to get past the self test with it connected.
Most of the newer power supplies have a thermally controlled PWM circuit to manage fan speed in order to reduce fan noise. If your supply will only latch without the controller, then leave it unplugged. Unfortunately, I can't provide an explanation for why yours is failing the POST with it connected. The fan may be tied directly to any of the 12v rails or one of the 5v rails for that matter. Running the fan at 5v won't hurt it; it simply slows it down.
The specs on 80mm fans usually list ratings in the 25 to 30 CFM range at full RPM (which I generally don't believe, BTW). Consequently, a fan rated at 25CFM will evacuate the PSU case about 450 times a minute. But, keep in mind that PSU fans are also used to provide case cooling in addition to PSU cooling, hence the excess capacity. Running the fan slower on 5v will still provide more than enough air flow for the PSU alone and it will be quieter.
andrew