Unscrew cover of mainboard with a Cross-head screwdriver.

Check if terminal in PCB area is pushed to final position.

If not, reinsert it to final position.

Set multimeter to resistance gear.

In PCB area, measure the resistance of defrost temp. sensor with a multimeter.

Take note of value.

Measure the temperature of freezer air duct, near the defrost temp. sensor. Use measured temperature to find the standard resistance value in Temperature- Resistance Chart for Sensor.

Remove all freezer drawers.

Remove all glass shelves.

Unscrew the screws on air duct.
a. Check the freezer air duct to find the three screw covers.
b. Remove the screw covers (total of three) on the air duct with slotted screw driver.

c. Unscrew the screws (total three) with Cross-head screw driver.

Dismantle the air duct.

a. Catch the bottom of air duct and pull down the air duct.

b. Pay attention to the connectors when pulling out the air duct.

c. Disconnect the terminal for fan motor.
Disconnect the terminal for freezer temp. sensor.

d. Move the air duct out of the freezer compartment.

Check if terminal is inserted to final position.
If not, please re-insert it to final position.

Check if sensor is attached in proper position, as showing in picture.

If not, correct it.

Check if wire of defrost sensor is broken.
If yes, replace it with a new one.

Disconnect terminal of defrost temp. sensor.

Check if the terminal is stuffed with foam.

If so, use tweezers to smash it and remove.

Measure resistance of defrost temp. sensor from terminal in freezer, and take note of it.

Measure the temperature of defrost temp. sensor.