That just happened to me last week. I swung by a friends to demo a floor box she didn't want before the new carpet was put down the next day. I figured I could squeeze it in before my final at school the same night. Rather that trace out which circuit I threw the main. On my way out I turned it back on and wouldn't you know it, the thing would not reset. I don't know if it was from not being exercised or if it just broke. It did not sound to good inside.