I have a GE GSS22JETEWW side-by-side refrigerator that has been working without issues until last week. Suddenly, liquids on the top shelf of the refrigerator side (milk, water, juices, etc.) were freezing.

I first bought some thermometers and observed the following over a few days:
Refrigerator Top Shelf: around 22-24 degrees F at all times. Too cold.
Refrigerator Bottom Shelf: around 32-34 degrees F at all times. Still too cold.
Freezer, middle shelf: around 10-12 degrees F at all times.

I read various posts in this forum and watched the wonderful repair videos on AppliancePartsPro (APP). I have bought several parts, including thermistors, defrost thermostat, damper, and even a main control board from APP.

Then I did all the following -- all to no avail.

1. Replaced the refrigerator thermistor. I tested the old thermistor by putting it into a cup of ice water, and it did show 16K ohms (within spec). I did test the new one, too, and it was within spec.

2. Replaced the two freezer thermistors (top and bottom). They were of the "old" kind with the black bottom, so it was just as well that they were getting replaced with new. No change.

3. While replacing the freezer thermistors, checked the evaporator fan -- it was rotating without obstruction. There was minimal frost on the evaporator coils.

4. Checked the evaporator bottom to make sure there was no blockage for the intake of air. All clear.

5. Checked the damper. The GSS22JETEWW has a Mylar damper, not an electrical damper. I confirmed that the Mylar flap was present and not stuck. I did not replace the damper, as nothing seemed to be wrong with it, and it was not an electrical part.

6. Replaced the main control board with new. No change.

7. To confirm that the defrost thermostat and defrost heater are good, I unplugged the refrigerator and probed the blue wire on the AC connector side and J7, pin 9. Resistance was 25 ohms, again within spec (approx. 22 ohms). I do have a new defrost thermostat but did not install given the good results above.

8. Removed the cardboard panel at bottom rear, and visually inspected condensor fan. No blockages, and it was rotating fine under power.

9. Touched the compressor -- it was working (I noticed that it was quite warm to the touch -- is that normal?). Again, remember the freezer is cooling at 10 degrees F--but shouldn't that be 0 degrees F per spec.

10. Set the digital refrig and freezer temp controls from 5/5 to 3/3, waited 24 hours. No change.

What should I try next?

-- Mark