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I bypassed the circuit board and manually tested the heating element and it came on. But how can I test if it’s coming on its own ? How can I check that the mother board temp control relay if in fact is working on its own ?
Please tell us what your symptoms are. I’m not sure I understand your problem. Cause 1 Defrost Control Board The defrost control board determines how often to run the defrost cycle. If the board fails, the refrigerator will not go into the defrost cycle. Before replacing the defrost control board, first test the defrost heater and defrost thermostat. If the defrost heater and defrost thermostat are working properly, the defrost control board is likely defective. Cause 2 Defrost Timer The defrost timer turns on the defrost heater several times throughout the day to melt any frost that may have accumulated on the evaporator coils. If the defrost timer is defective, it may not advance into the defrost cycle, or it may not send power to the defrost heater during the defrost cycle. To determine if the defrost timer is defective, slowly advance the dial into the defrost cycle. The compressor should turn off and the heater should turn on. If the timer does not send power to the defrost components or advance out of the defrost cycle within 30 minutes, this indicates that the defrost timer is not advancing. If the defrost timer is not advancing, replace it. Cause 3 Defrost Heater Assembly The defrost heater assembly turns on several times throughout the day to melt away any frost that may have accumulated on the evaporator coils. If the defrost heater assembly is defective, the defrost system will not work, and frost will continue to accumulate on the evaporator coils. To determine if the defrost heater is defective, use a multimeter to test it for continuity. If the defrost heater does not have continuity, replace it.
Connect a low load test lamp parallel to the heating element and route wiring out of fridge compartment so that when heater turns on the lamp lights up outside fridge. In this way you can note how long defrost cycle runs. can use decoration led lights used in parties instead of lamp. If you want to verify if control board is initiating defrost cycle or not, connect test lamp at board end.
Hi Carlito, Did you ever find the issue? I’m having the same problem where the fridge will not automatically defrost but I can get the control board to enable the defrost by manually entering into the troubleshooting cycles.
From what I can remember after replacing all temp sensors I replaced the circuit board and it corrected issue.
