Referigerator warming up and not defrosting

Replaced the thermosdisc (Fuse-M) and waited a week and the refrigerator never defrosted. Looked at Mother board and found a burned spot. Ordered motherboard and replaced .Now we are just waiting to see if will defrost by itself after I defrosted the coil before starting it up after replacing the mother board. Been 3 days so far and still ok. The refer. is 62 miles away , one way.