Frigidaire FPHG2399MF6 Frige Warm, Freezer cold, evap coil not defrosting

Refrigerator & Freezer Repair
1

Please make sure to click on General above and select the correct FPHG230appliance type first.

Brand: Frigidaire
Model Number:FPHG2399MF6
Main Symptom: Evaporator Coil not Defrosting
What happens & when: Evap coil frosts over resulting in warm fridge. Heater resistance is 26 ohms which is correct per service manual. Replaced thermostat and main control unit, same problem occurs; system seems to respond to manual defrost action..

Error Code (if any): none
Parts or tests already tried: heater tested, thermostat replaced, main control & power board replaced.
XPhotos / video link:

2

Have you checked to ensure the defrost drain isn’t clogged

3

Yes, but I’ll check it again to be sure.

4

Then verify 120v ac is getting to the defrost element when it is manual mode

5

The defrost drain is clear. There is 120vac at the heater terminals in manual defrost mode so the thermostat is conducting. The heater got hot and melted a portion of the ice but the coils were totally frozen over. There is 115vac at the heater terminals when the refrigerator is turned off.

6

But it is not commanding the element on during normal operation? If that’s the case then you have a logic fault in your board

7

Main power control board ( Frigidaire 241996354 Refrigerator Pcb Main Power Control Board Assembly | Genuine OEM Part ) sadly it is no longer available

8

Thank you! I found a new control board at a local supply house; it was manufactured in 2011 so it could have an infant mortality type failure but it seems unlikely to me that it would have an out-of-the-box problem exactly like the old board. I replaced the door gaskets to see if that makes a difference.