Entrance of drain pipe is covered by freezer air duct, you need to disassemble freezer air duct and remove evaporator to check it.

Remove all drawers.

Remove all shelves.

Remove the vertical partition plate:
a. Insert 2mm slotted screwdriver into the gap;
b. Lever up the cover plate from bottom;

c. Insert 2mm slotted screwdriver into the side gap;
d. Lever up the cover plate from bottom;

e. Pull the bottom end of cover out;
f. Pull the top of the cover out;

g. Take pipes out and pull them into a horizontal position;
h. Push the latch down and lift top out of the cavity;

i. Push the latch up and pull bottom out of the cavity;
j. Pull the partition outward and remove partition;

k. View of interior once partition has been removed.

Dismantle the air duct.
a. Hold the bottom of air duct;
b. Pull air duct out from below;

c. Disconnect the terminal for fan motor;

d. Disconnect the terminal of freezer temp. sensor;

CHECK AND TEST 1

e. Remove air duct.

Check to see if heat-conducting wire is missing.

Pour water into drain pipe to check if it is blocked with foam.

Use metal rod with tip head to smash foam in drain pipe.

DIAGNOSIS 2

When installing the air duct, make sure to move wires out of the way to prevent crushing by air duct.

After pushing the air duct into position, you should hear a click sound. If not, repeat again.

Check to see if there is a wide gap between air duct and cabinet.
IF SO, install air duct again.

Check to make sure latches are inserted into cavities properly.

First, insert top of cover plate into the gap, then bend plate to insert bottom end. Lastly, push middle into slot.