Michael S Pinole , CA February 28, 2015 Appliance: Jenn-Air Refrigerator JCB2389GRS Jenn-Air Refrigerator Jcb2389grs: Defrost control board. How to replace Defrost Control Board. I followed the instructional video and itr was easy . Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes