8-pin atx to 4-pin atx - Rocketfish 550w psu?

in my experience w/ this pin-out, if it doesn't work, that's not the problem. i found thet in some cses, your motherboard has the clear cmos on the wrong jumpers when shipped and wont start this way. you can unplug everything and jump th egreen wire in the middle of hte 24 pin to any black and see if the psu will power up, just to eliminate this as the source of your issue first. then after double checking the cmos jumper, start plugging everything back in but only neough to start things up, the 24 and the cpu, and try it then, before you installl or plug anything else in. then go from there w/ more trouble shooting methds, but the 2x4/2x2 most likely isn't the issue.