Evaporator fan not working.
We have a Samsung RF28HDEDPBC/AA refrigerator that is not keeping the temperature cold anymore.
The freezer is fine, but the refrigerator on top is warmer than the temperature shown on the display. It is set for 34 degrees, and the display shows 34 degrees, but the air inside the refrigerator is about 52 degrees. (I used a refrigerator small thermometer as well as an external digital thermometer that has a sensor attached with a wire.)
I removed the evaporator cover, the coil had a little frosting over, I think that would be normal , since the coil was cold and I had the doors opened for a while before I managed to remove the cover.
I tested the sensors (one inside the cover and one on the evaporator) and they are both working fine, the resistance at room temperature and at 32-ish degrees are within normal ranges.
While I was testing the two temperature sensors, I disconnected both of them, and the refrigerator was still showing the temperature as 34 degrees.
I tested the fan by applying 12V DC and it works fine.
I hooked up my voltmeter to the fan wires and set my phone to record a video of the voltmeter, then I closed the doors. As far as I know, with the doors closed the fan should be powered up, but the voltmeter never showed any voltage with the doors closed.
Next step, I used a 12V DC power supply and I "hot-wired" the evaporator fan directly, now the fridge is actually making the set point.
My questions are:
- how does the refrigerator "know" the temperature inside the refrigerator ?
- will the fan be turned on and off based on the temperature reading, or would it run all the time, as long as the doors are closed ?