I have a problem with my side by side Samsung RS21Fans. The temperature in the refrigerator goes up and down to -4 degrees and the power cool automatically turns on and off. Everything is fine in freezer. I have replaced 3 sensors (temperature sensor sensor for air duct, thermal fuse fuse 110 ° C and Defrost Heater Sensor Thermistor Thermal Fuse Kit RS21); but the problem still exists. Can somebody help me?