Having problems with rising freezer temps and HOT mullion , read on another thread about replacing a circut board , I’m assuming its the board in the back closest to the fan? The operator @ Kitchenaid gave me the # for electronic control board , but that is inside the refrigerator the top where the temp controls are located. 
I set up a household fan in back of the unit and it seems to keep the “hot” frame from occuring but the freezer temp still rises (usually to about 18 degrees before cooling itself back to 0). The cooling fan itself will occasionally be idle but a little flick of the finger will get it moving . Is the above mentioned circut board a possibility?
thanks , Dave