My freezer is working but I notice frost build up on the back. The refrig (fresh food) side is warm. I followed some of the other threads but cannot find the defrost time or heater on the diagrams for my model. I did manually defrost the refrig/freezer and this cured the problem for about two days , I then noticed the fresh food side again become warmer and frost build up on the freezer side. Could the adaptive defrost be the problem? Thanks in advance