How do you test the ADC board to tell if it isn't working?
Answer Hello Cathy. If the unit is not defrosting and the heater and thermostat are good, then the ADC is bad and will need to be replaced. You can test this with a multi-meter TJMA-DMT3. Here is a link on how to use a multi-meter. http://forum.appliancepartspros.com/oven-repair-including-ranges-cooktops/4810-how-check-continuity-ohmmeter.html