I removed the cover and tested all 3 safety/interlock switches and determined the primary switch was defective. I ordered the correct replacement switch along with a couple of other items for backup repair items if needed later. When I received the correct replacement switch I installed it and tested all 3 switches again to ensure they were all operating properly with the bad switch replaced. Once this was done I tested the fuse along with the Diode before reinstalling the cover. Once together and secured properly I tested the unit with good results of a unit operating properly again.