there are alot of electronics and safety devices on these suckers... have you read thoroughly the owners manual or troubleshooting section? I know electricity is very important for fans and motors and old or faulty wiring can glitch things up pretty easy. I assume you have all doors closed properly and nothing is compromising the air tightness (which could trip one of the door sensors or something). I would first try to review ALL your owners manual stuff carefully while we wait for someone to come on here who has experience with your exact unit. GL!