On the back of this box is a control board behind a metal panel. Open panel and test the fuse on the lower left side of control board. This boards are static electric sensitive, so take care when touching or handling. The board are readily available at the parts houses that help sponser this site. Around $175. Another alternative, if you have any electronic savvy is to remove the fuse and replace it with a fuseholder & fuse 250v 15a.