LG LRSC21935xx, Service Manual

Page: 100 / 128

TROUBLE DIAGNOSIS
- 100 -
Problems
Symptom
Causes
Checks
Measures
Remarks
Bad defrost.
Defrost is not
Defrost lead wire is cut.
Check if defrost lead wire is cut with a
Reconnect Lead
working.
tester.
Wire.
Defective defrost driving relay.
Check the voltage of CON2 (1 and 7)
Replace relay (RY 7
Refer to load
with a tester after pressing main
and RY 3) or PCB.
driving conditions
PCB test switch twice.
check in circuit
If the voltage is normal then it is OK.
explanation.
Defective defrost sensor parts.
Check the resistance of defrost sensor
Replace defrost
Refer to sensor
with a tester.
sensor.
resistance characteristic table of circuit explanation.
Defective
Buzzer
Defective connecting lead wire from
Check lead wire related to door
Repair lead wire.
buzzer
continuously
main PCB to door switch.
switch with a tester.
rings or door
Defective door switch parts.
Refer to door switch in parts repair
Replace door switch.
opening alarm
guide.
does not work.
Defective
Buzzer does
Key input wire is cut or bad connector
Check input wire with a tester.
Reconnect lead
Refer to display
display button
not ring and
terminal contact in main PCB and
wire and replace or
circuit in circuit
key does not
display PCB connecting lead wire.
directly connect bad
explanation.
sense even
contact terminal to
button is
lead wire.
pressed.
Key is continuously depressed due to
Disassemble frame display and confirm
Adjust or replace
structural interference.
visually.
interfering structures.