I've built two new identical computers fom scratch today at work (funfunfun)... i breadboarded the first PSU before putting it all togther, all good. However, once i'd finished and tried to bootup, all i got was a flash of all the mobo lights and the CPU fan twitched, but nothing more. After much frustration i gave up and replaced it with the other brand new PSU, which worked fine.
Now building the second machine, i figured i'd check to see i wasnt mistaken. Breadboarded the new mobo with the dodgy PSU, and it worked fine again! So i built the second machine, trying to boot every now and again to check it wasn't going to fail again once id finished... and LO AND BEHOLD, once id finished putting it together, it wouldnt boot! Same symptoms!
So, i disconnected the PSU from everything and got it out of there, tried breadboarding again, still didnt work. But then I tried again after five minutes and it did. My first though is its just faulty... but are there any other possibilities before i RMA?