I have had about a 96% success rate in these used power supplies. I have yet to have one of these breakout boards go dead. Even the prototypes I received back in December are still ticking strong and have many hours on them now. The breakout board has nothing to do with the fans at all, that is all done inside the power supply.

So if you see one light with the power switch flipped to off, then when you switch it on you see two green lights, and still have no fan - it is most definitely the power supply.