GE refrigerator food side not cooling

The food side of this GE side by side will get warm. The damper door will be closed.The freezer is cold and making ice etc. If I pull the power and replug it in the damper door will open and the food side will get cool again,but after a few hours will become hot and door closed again. I have replaced the main board and the thermistor in the food side with no luck. Is this the damper door failing? Or am I missing something? Thanks