Thread: Samsung rb1955sw compressor doesn't shut off

The more I think about it I suspect the display board's set point switch is going directly to the main board and not through any firmware on the display board itself. And since I can change the set point then it's obviously reading it. Don't know how such a simple thing could get so complicated. I'm going to recheck all the grounds. Maybe we had a mouse attack.

The only thing I can think of is replacing the sensors in the freezer to see if that will resolve your problem. There's nothing to test the display panel with. It only instructs the control board what to do, nothing more. The part number for the sensor is DA32-10105CC. It is possible that the sensor may act weird at certain times for no reason at all. The control board will not give an error code unless the sensor is either open or shorted.

O.K. I've ordered the part but I'm confused about its function. I don't see it on the circuit diagram. There's a defrost sensor and a thermistor by the freezer coil. This thing is located in the box that holds the light and supports the ice maker. If I unplug the sensor I get a 'f5' error and the unit shuts off. I took it out of the housing and plugged it back in just letting it hang and turned on the power. After it got cold I opened the door slightly and grabbed the sensor and held it tight in my palm to heat it up. The reading on the door did not change after several minutes but I could feel the sensor was much warmer. I guess the display is reading the thermistor? Then what does this sensor do?

The sensor is located in the wiring schematic for all 4 sensors. The one that's in the light housing is for the F-Room Sensor. CN30 connector: Blue - Gray on the control board. This is the one that senses temperature in the freezer for the control board. The temperature display will not change if you try to put your hand on the sensor unless you pull the plug and replug it in. That is the only time the display will tell you the exact temperature of the freezer. The display will return to the set temperatures and stay there. Once you change the sensor, you should be ok since the board has been replaced.

The defrost sensor is only for the function of the defrost circuit when it is actuated. That's a totally different circuit. It will tell the control board once the evaporator temperature reaches about 50°F and tells the defrost circuit to shut off.

O.K. I thought it was the therm (thermistor?) next to the defrost temp sensor that was going to cn30. Should have checked with my new meter. I guess it's the therm I don't see on the diagram unless that's the heater but I also see a connector on the drain pan which I had assumed was the heater. Inquiring minds want to know. After cycling power, I can watch the display as the temps drop until they're past the set points (fridge stops at 38). Once the overload trips (or whatever is happening) the display returns to the set points and stays there even if the unit returns to ambient until I cycle the power again which I guess is what you're saying. Thanks so much for your help.

I'm thinking the display must stop getting updated when the door is open. When I did my experiment the freezer was at 10 when I opened the door and grabbed the sensor. It did not change as I said but when I closed the door it jumped up to about 40 then came back down pretty quickly.

Installed the new sensor - yep, you guessed it - same f#*+&#ing problem.

You're not going to believe this!!! I just got off the phone with Samsung tech support and they say that there may be an issue with the door switch on this unit. They suggest actually disconnecting the door switch. So pull out the door switch and pull the connector off it. The control board will see that the door is closed and it should resolve your problem. This is only a 5 volt circuit so there is no need to worry about shorting anything out. The only thing you will have is no lights in the refrigerator when you open it. Let me know how this goes.

Didn't fix the problem although the symptoms have changed. The switch was bad as verified by my dvm but it was 'open' so it appeared the door was always closed. After pulling the switch Saturday I thought it was working but when I got up Sunday morning the freezer display was flashing -2 and the actual temps were 59 and 38. I took the switch apart and cleaned the contacts and stretched the springs out and reassembled it and verified that it now worked with the dvm, I reinstalled the switch and again it appeared the unit was working but was flashing -2 again this morning. I'm going to reinstall the original main board and see what happens. At least we found a real bad part but since it was 'open' it doesn't make sense that it would cause the problem.