Power the whole thing down, let it cool and make sure the power supply is not too hot too (hot PSU sometimes means the voltages go wobbly, and causes the ASIC chips to register as failed). I had that happen and a cold-reset got it back working again.. after some heart stopping moments!
Thanks, I actually powered the entire thing down, let it cool, checked all of the connections and used canned air on it to make sure to get any dust off and out of it. It is now hashing correctly once again.