Level of DifficultyA Bit Difficult
Time to do repairMore than 2 hours
Age of ApplianceMore than 10 years
evaporator coils were frozen solid and air wasn't flowing across them
read all directions first, then consider which steps you'd like to take
in any case...
- check for blockages in the upper and lower air vents that allow air from freezer side to cool the fridge-side
- inspect that the fan in the freezer side is actually turning and not blocked
- if no blockages and air is flowing between the sides...
- unplug the unit
- remove all goods from freezer and fridge
- remove freezer side racks
- remove rear panel on freezer side using philips screwdriver (note that the ice-cube tray motor housing must be freed by removing its screws. it can be pull out a bit to get to a single screw holding the top of the rear panel in place)
- allow the evaporator coils to evaporate all ice off, checking the drain pan under the fridge frequently - accelerate the process using a hair dryer or paint stripper (heat gun)
- disconnect the white wires from the connection block located about 2/3 of the way up the rear wall and check resistance using an ohmeter (see specs on back of fridge on circuit diagram)
- if you get a very high resistance reading, the heater element is likely broken. if so...
-- remove the 2 metal shields located horizontally across the evaporator coils (behind them are the two series-connected defrost heater elements)
-- visually inspect the elements - if they are discolored green or black, remove and inspect more closely (most likely they are blown, just like a light-bulb filament that shows black on the glass)
-- if you see nothing, remove them anyway (since high reading) and check connectors
-- replace them (likely only $30 to $75, depending on type)
- if coils seem ok, or if not suspect, check the defrost thermostat WHILE IT IS STILL IN A WORKING/COLD FREEZER.
- get the defrost thermostat into a coil chamber (other freezer or bucket of ice?) and check resistance using an ohmeter. It must be WELL-BELOW 40F to test it. When it is truly immersed in cold (as it would be in a working freezer), test the resistance. it should be 0-ohms when <<40F and some much higher resistance (>200KOhms) when > 40F.
- if not, replace it
-lastly, if neither the defrost heater elements are bad nor the defrost thermostat is bad, open up the defrost timer
-- the defrost timer is located in the fridge side, likely with the fridge thermostat knobs/controller
-- it is a 5-pin part that cannot be repaired. If all else is checked, most likely the defrost element is never coming on because the timer is not turning it on