To determine if the... defrost sensor or fuse is defective, use a multimeter to test both the sensor and fuse for continuity. The main control board regulates the power supply to all of the refrigerator components, including the defrost system. This video shows the proper way to test your defrost thermostat. When the refrigerator stops going through the automatic defrost cycle the refrigerator will not cool properly because the frost will block the air flow on the evaporator coil and cause the cold air to stop circulating. The defrost sensor has a fuse to back up the sensor in case the sensor fails. If the defrost sensor fails to shut off the defrost heater, the fuse will blow in order to shut off the defrost heater. The defrost thermostat monitors the temperature of the evaporator coils. The defrost sensor has a fuse to back up the sensor in case the sensor fails. The defrost thermostat is usually located behind the back panel in the freezer section of the refrigerator, and it is usually clipped onto the evaporator coil.Get Social With us!https://www.facebook.com/PartsDrhttps://twitter.com/parts_drhttps://plus.google.com/+PartsDrCheck out our appliance repair forum: http://forum.partsdr.com/Check out our blog: http://partsdr.com/blog/Subscribe to our YouTube channel: http://www.youtube.com/subscription_center?add_user=thepartsdrIf you found this video helpful please click the thumbs up button and leave us a comment below. If the board fails, the refrigerator will not go into the defrost cycle. Hold times are long. As a result, the thermostat won’t provide power to the defrost heater. Control boards are frequently misdiagnosed—before replacing the main control, first test all of the defrost system components. In the defrost cycle, the defrost heater melts away any frost that may have accumulated on the evaporator coils. How to test the sensor for electrical resistance with 2 temperature guides. This video from Sears PartsDirect shows how to troubleshoot problems with your refrigerator's thermistor or temperature sensor if your refrigerator is not cooling at the right temperature. The defrost control board determines how often to run the defrost cycle. When the coils drop below a set temperature, the thermostat contacts close to allow power to flow to the defrost heater during the defrost cycle. If the defrost timer is not advancing, replace it. The temperature sensor is used to monitor the temperature in different areas of refrigerator and freezer including monitoring the temperature on the evaporator coil for the automatic defrost cycle. Shipping all 7 days! The sensor shown in the video is Part # DA32-10104N (PD# PD00026468) but the instructions in the video applies to many different part numbers and models of Samsung refrigerators. Step-by-step instructions on how to test temperature sensor in a Samsung refrigerator. 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 thermostat is defective, the thermostat contacts will not close. To determine if the defrost heater is defective, use a multimeter to test it for continuity. Before replacing the defrost control board, first test the defrost heater and defrost thermostat. Learn how to test the thermistor to see if it's working. Step-by-step instructions on how to test temperature sensor in a Samsung refrigerator. We've got millions of parts, hundreds of brands, and thousands of step-by-step videos— everything you need to find it, fix it and finish the job right. Already ordered? If the defrost heater assembly is defective, the defrost system will not work, and frost will continue to accumulate on the evaporator coils.