The furnace control board has no activity on it's LEDs. I have no command of heat, cool, or fan. I started with resetting the breaker, then tried a new digital thermostat. I also tried attaching the thermostat to the furnace with a new piece of 24" wire to try and eliminate a short. I checked power to the door switch and checked fuse and all seem good. I have the same power input level from door switch to circuit board to transformer line in. I have zero power coming out of the transformer load. I have tried a new circuit board which bought me to a new model 83M00. This replacement board has a yellow/green wire that is extra, there was nothing in the install directions regarding this wire. I have also tried a new transformer. What seemed like an easy, logical fix has not turned out to be so. Any suggestions would be appreciated, I don't think our space heater is going to keep up with the arctic chill headed our way. Thanks.