Can you even update the bios while there is an error occouring?
If i understand right you can flash the bios without anything else but psu.
=> Try that, maybe the error stops flashing?
Have a look here if you havent already:
http://rog.asus.com/forum/showthread.php?5889-Error-Code-FF-ASUS-RAMPAGE-III-BE-i7-990x-3-x-4GB-Cors...Especially: #9
"The only thing that might save this is removing the CPU from the socket and then clearing CMOS. Reinsert CPU, mount cooler and use a single module of memory again to see if the board will POST.
If that does not help then RMA the board.
-Raja"
//////EDIT
Another thing:
Did you try the board outside the case? (The motherboard box makes a good stand)
=> Some cases short the mobo, especially with the big backplates at the cpu vrm.
Check that out too
🙂