I have a side by side fridge. Its only cooling the lower portions of both. I looked where the defrost board is located and have found two of the wires on the connector that goes into the board have some soot on them. We had a lighting storm two days ago that took a T.V. out to. My question is do you think the defrost timer board is bad?
Yes, your adaptive defrost board probably is bad. You are lucky it's still running.
Pull freezer back panel and defrost coils. Check defrost heater and thermostat. If heater ok , just change the thermostat and adaptive defrost board.
Half Cooling 
