Just a quick thought...sometimes proprietary computer cases have a sort of kill switch inside them which prevents them from booting up if the case is open. Did you a) notice anything like this when looking around inside, or b) have the case open when you were testing the new PSU?
I didn't notice any sort of switch to what your discussing, Curtis. Your implying that if I changed the PSU and had the case of it might have not booted because of this.. Well yes I had the case off when testing it with the new PSU... But I didn't see a switch inside and I don't think this comp would have one if you said "sometimes properietary computer cases.." since this is an older pc.
All is good... I still have the psu, when I get time maybe I will put the case on and try but I doubt it will do anything. I think the mobo is gone.
Don't worry about it. I find it unlikely that it has such a switch. The switch I was referring to was simply the power switch. I've seen them go bad, but that's easy to test since the two pins for it are right on the front of the motherboard.