Hi, my Frig side gets warm, while my freezer stays cold. there is a evaporator coil at the bottom on frige behind the lower draws that keeps iceing up. I changed the mother board and the defrost timer is freezer. There is another defrost heater in freezer on evaporator coils that checks out ok. but the evaporator in the botton of frigerator does not have a defrost timer on it. so when I replace the mother board and use a hair dryer and defrost the frozen up evaporator coil in lower refrigerator it keeps the refrigerator perfect at 36 degrees as normal but after a few weeks it starts iceing up again. Im lost do you have any ideas?