Your not giving us enough information. Did it not work with the old psu?
Why did you replace the psu?
I would not turn on with the old PSU which is why I bought a new one, in hindsight I dont think I needed a new PSU. I breadboarded the system, I jumped the 24 pin connector, pin # 16 with a black wire. The system came alive and I was told, won"t mention who in case its wrong, that the MOB was bad. So, I went out and bought a Asus P5G41T-M LX Plus for $39.96 and some DDR3 for $24.99. Not the top of the line, but it will have to suffice for now. Tell me that the money spent was not wasted, at least until I have gotten the PC back together.
I await your response!