Daniel J West Melbourne , FL November 27, 2014 Appliance: Frigidaire Refrigerator FRS23F4CW3 Frigidaire Refrigerator Frs23f4cw3: Evaporator fan turned on and off for several minutes and then eventually started. How to replace Adaptive Defrost Control Board. I first replaced the evaporator fan but the problem wasn't fixed. All that was left was replacing the Adaptive Defrost Control Board and it the evaporator fan now starts immediately. 113 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: 15-30 minutes