Finding your refrigerator not cooling is never a good situation, repairing it on your own on the other hand and saving a considerable amount of money at the same time is a good thing.
The range of different model serial number’s on the market, are by far way to many to keep up with. This list of the most common refrigerator not cooling causes:
-Bad wall outlet
-Dirty/Clogged condenser coil
-Open cold control
-Shorted adaptive defrost control board
-Open defrost thermostat
-Defective defrost heater
The cause’s listed above are what technician’s repair and replace routinely. Having a multimeter available to test the electrical circuit of your refrigerator will aid in the proper diagnosis.
If you notice frost on the back wall of the freezer and the refrigerator is not cooling you have a defrost issue. The multimeter will help you verify which component in the defrost circuitry has failed.
The defrost thermostat will read less then one ohm and the heater should read around 30 ohms. Testing the defrost thermostat or the defrost heater with a wire connected, could lead to false results. Always disconnect one wire before making any test with the multimeter. Disconnect or unplug the unit before servicing.