Well,,,,hmmmm NOW it sounds like a bad psu, Before it didn't. Ok just leave the board in the case for now. Unhook the motherboard 20/24 atx connector. Unhook the 4pin p4 connector as well. Now find the green wire on the 24pin connector and jump the green to any black and if the psu is good it will run, If its DOA it won't. Let me see if I can find a picture. (don't worry its only 5 to 12 volts dc)