Not cooling properly

The damper valve controls how much cold air from the freezer evaporator flows to the fridge compartment. If damper is stuck OPEN, fridge gets overcooled or even freezes food. If stuck CLOSED, fridge doesn't cool at all. The damper is thermostatically operated — it opens and closes based on evaporator frost level and return air temperature. You cannot directly control damper with electronics; it's a passive thermal device. Symptoms of damper failure: one compartment too cold/too warm while other is fine, or temperature swings between compartments. Test: manually check damper position during operation (may require partial disassembly) to verify it moves.

Defrost cycles typically run multiple times per day — approximately every 6-8 hours depending on compressor runtime and frost accumulation. Each defrost lasts 15-30 minutes. If you notice compressor running for extended periods without normal cycling, defrost system may be blocked or heater may be failing. Check for ice buildup on evaporator coils during operation — this is normal but should completely melt during defrost.