I turned off the refrigerator since the evaporator coil had accumulated a lot of ice and needed to defrost completely. It was frozen to point that it would not allow airflow and verified the evaporator fan was working. While that was defrosting, I thoroughly cleaned the coils under the fridge. I then installed the new control board and plugged the refrigerator back in and confirmed there was airflow to the refrigerator compartment. A week later and the refrigerator is maintaining proper temperatures.