You can try powering up just 1 main Blade. If it powers up 1 blade, at least you can keep mining while you go get your new PSU.
Oh, also, if you are just powering up 1 AntMiner only, you can use 450W and up!
The ATX kept shutting down after cpl of minutes. Then re-enforced with more wires from molex (using extenders), same thing. Happened in the past as well when i was trying to use many fpgas with this PSU... Its single rail 550W psu (it claims +12V to have 528W output)
I guess im going shopping for proper PSU... perhaps one of those dedicated 12V thingies.
Yeah the jumper is in place fine.... currently i disconnected the second blade. (both power and the ribbon). First blade is running stable. I guess tomorrow ill but a decent SMPS.