Lots of different possibilities for trouble spots, so I ordered and received the most likely failed part(s) and we really wanted to get the thing running properly anyway. Took a day or so to get all the ice melted. Replaced lots of parts, hoping to get it working properly so we could keep it for awhile. Is now up and running. Seems fine now. Some of the parts were exact fit, others needed extra attention. We were aware that due to the age of the refrigerator there could likely be other parts ready to give out, so we tried to identify those most likely ready to fail and thus replaced parts that were still working but getting on into their usefulness. Parts replaced were ice maker, defrost heater kit, defrost timer, defrost thermostat, dual water inlet valve kit. Was a challenge sometimes, working in the narrow freezer, making parts fit. Cost was sort of high, but much cheaper than buying a new refrigerator. The instructions accompanying the parts were missing for a couple of things and did not cover everything encountered. Under "tools" below, I also used some pieces of plastic, glue and a rivet gun.