We have a Frigidaire model FRS23R4A, about 20-ish years old, kept in the garage and mostly used for drinks, bulk frozen foods, and overflow from kitchen. A couple months ago, I went to get something out and noticed the food in the freezer was mostly thawed. Lights were on but I couldn't tell if the compressor was running. I couldn't hear the compressor running so I checked the relay continuity and it appeared to be bad, so I ordered and installed a replacement. Also cleaned the condenser coils and parts under the fridge.

The compressor definitely runs now, the evaporator coils get frost on part of them (is that normal or should the entire coil get frosty?), but it's still not freezing. I thought maybe the evap fan was bad because the voltage to it was very low and I never saw it running, so I replaced the control board.

I can see the fan will run now, but not very often. The freezer is still not freezing so I'm not sure what else it could be.

If it's low on freon, will the coils still frost over? I've noticed since I replaced the control board that the fan hasn't been running. I'm going to try replacing the fan motor first.