Got a new seasonic 600w psu about a week or so ago. Any way, plugged it in, plugged in all my drives etc and turned it on. the pc came on fine and started booting, then i suddenly realised my fans weren't spinning as i'd not plugged in my fan controller. So i turned off the PC mid boot, plugged in the fan controller and tried to turn back on. But nothing. The PSU would simply not power up. I tried various things, and tried leaving it off for a while...no joy. So, very frustrated, i unplugged it and put my old enermax in and it booted fine. Then a few days later i was about to rma it when i thought i'd try it once more. And it worked fine. I only plugged in the main power connectors as i was short on time, but it powered up no problem. Today i've finally had some time to put the seasonic in properly, plugged it all in etc, booted up .... BEEP BEEP BEEP...arrrgghh, i'd forgotted to plug my graphics card in. So i had to shut it down...plug the card in....then boot back up. But again, i couldn't boot back up. The PSU won't power on at all! There is a light showing on my motherboard, which goes off when i completely unplug the psu, so i'm guessing there's something going on there. What's the story with this? Because it's a new psu does it need to be left running for a bit before shutting down? Obivously that had been my intention but i made the schoolboy error we've all made with the gfx card. Any ideas? I'm back to my enermax atm, but i'll probably give the seasonic another go later tonight after work.