Maytag model# MZD2766GEW Serial # 19404011AT. Ice builds up on the evaporator and after period of a week air flow is lost and refrig becomes warm. I removed the cover on evaporator in the freezer and find the evaporator is one big block of ice. I defrosted the evaporator and it runs for a week to 10 days then ice build up all over again. Any ideas on what parts may need to be replaced.
There is no way to easily test the adaptive defrost pc board in the control panel, but you can test the defrost heater and thermostat for ohms when the item is cold. If open, replace it AP4069923. If ok, replace the adc board AP4070403