David A Naples , FL December 07, 2015 Appliance: Frigidaire Refrigerator FLSC238JS0 Frigidaire Refrigerator Flsc238js0: Freezer would not defrost. How to replace Pcb Main Power Control Board Assembly. I first replaced the thermostat, then heating element and finally the Control Board and now the refrigerator is running great. Determining it was the control board was a challenge, as it required replacing the other items in the defrost circuit first, this was time consuming. In addition locating the Main Power Board (which is under the Freezer section) and then removing it was tricky as you needed to lift the refrigerator a couple inches to provide clearance. Once the board was removed it only required unplugging the old and plugging in the new...that took just a couple minutes. 10 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: 2+ hours