I have a side by side refridge and freezer. Freezer side started to get warm. I always keep compressor coils coils clean. So that's not the problem. I've replaced the starter and capacitor on the compressor and that wasn't it because it does make frost on the inside coils on the back of freezer wall. The evaporator fan and condenser fans are working properly. The Problem I'm having is the coils only frost up on the bottom 3 coils and at the very top of coil where defrost sensor is builds up with a lot of frost! but doesn't get cold. The center of the coils don't get frost on them. I Ran about 8 hrs and frost doesn't build up on all the coils fully. I removed the Defrost Bi-Metal sensor from the top of the tube thinking this maybe causing it to go into a defrost mode to early but it still didn't make it frost up. Is it possible that something in the main circuit board is bad? that's the only thing that I can think of. I can only get about 40 degrees inside of freezer when running for like 10 hrs... Can I cut the wires to the defrost sensor and put together to eliminate it for now to see if this would then make frost on all the coils?