LG WT7200 Series Service Bulletin Booklet page 29

Defrost Heater Error (F dH) check method
Symptom
1. Error code 'F dH' 1. Check the Main PCBA Connect
2. Check the Defrost control part
3. Check the PCB output voltage
Check Point
CON3
Test switch
Part
Defrost Heater
TEST MODE 3
CON3
2 pin ~ 9 pin
nd th
24
Resistance [Ω]
35~40
Voltage [V]
110-120V