Asus P5B-Deluxe: Overclocking and Tweaking Guide
 

it seems Asus have a little known tweak that resets the board. Basically all you do is power on the board with no CPU for 10 seconds and this resets the board to factory defaults. If you have a none boot for some reason this may be the fix you need.

http://www.thetechrepository.com/showthread.php?t=41