4700
Hi, Dan. Don't know if this is the same board as yours; can't find a name on it. But this breaker is behind the sata ports. It's black plastic, about half an inch long, fourth inch wide, fourth inch high. You can see the top of the can set into the plastic. Saw something about it in a review sometime back or I'd never have guessed what it is; the only time I've ever heard of a breaker on a board.
Took the thing apart after I broke it off; three tiny metal pieces fell out of the can so it's probably just mechanical, but I can't be sure of that because one of the pieces looked like it might have a silicon layer. Too small to be sure.