The customer's complaint was warm fridge, cold freezer (this is a bottom-freezer model, with icemaker. It has digital touch controls located in the French-door refrigerator section). I jumped to conclusions and replaced the motorized damper which regulates fridge temperature in this model; I then discovered that the evaporator was completely iced up. After defrosting it manually w/heat gun, I checked the heater resistance; it's o-k. Further research revealed that there is no traditional defrost clock; it uses a module which I believe is part of the digital temp. control setup. I should note that the unit was subjected to multiple power failure events due to a prolonged northeast storm (happens a lot here on Cape Cod). What are the chances that the module is defective, as against the likelihood of a defrost thermostat gone bad? The thermostat is hard to check once the unit is defrosted to the point where you can get to the connections....

Thank you, denman! I've printed and saved the .pdf you sent, and will try forcing a defrost. Also, the sheet gives the protocol for checking the defrost thermostat using the keypad; I'll try that too.