Long story but appliance guy could not diagnose. Recommended changing touchpad control panel since it has the button issues. Admittedly he wasn't sure that would fix it. I had my doubts since many stories on the net of replacing motherboards with no fix, and inspection of both boards revealed no visible issues. Besides, this part is now unavailable from GE. I happened on a very helpful site, http://www.appliance-repair-it.com/refrigerator-thermistor.html which has a procedure for testing thermistors in ice water with a multi-meter. My thermister by the evaporation coil tested bad with high resistance (real easy to test comparing to resistance/temp chart provided). I replaced that and the freezer thermistor with new GE replacements from AppliancePartsPros. The freezer thermister was good however since I decided to replace the defrost heater anyway (icing issue), I was right there. Separately on the controller, I removed the panel, on the affected micro switches I popped off the back of the switch, small parts, but, there is a small brass disk within which completes the circuit when depressed to set temp. I cleaned the tarnish off the disk with brass cleaner, checked continuity and popped back together, and sealed with a dab of polyurethane. All working perfectly. Saved 4000 to replace the fridge and fix cost less than repair visit with no fix. Parts from AppliancePartsPros were GE replacements and worked perfectly. Minor soldering required for thermistors. I spent many days researching and deciding approach and ordering parts. Parts came promptly in a few days. With parts in hand, it took 3 hours to repair per above. My fridge has 4 thermistors to test, I think 3 is more common. All of this work obviously with the refrigerator unplugged.