Yes everything was connected, no the mobo was not shorted.
This will sound silly, i was expecting to do a full rebuild & reseat everything although it worked after I reseated the RAM & rear case fan.
Was able to install Windows and use it for 2 hours, upon rebooting for windows updates i got the same problem. Won't go past POST, no BIOS and won't boot. Holds for 5 seconds and then power cuts for it to repeat.
Pretty sure its either faulty RAM/BIOS needs updating, I'll be looking at it again this evening and update this thread incase others have the same problem.