LG LMHM2017SW Service Manual page 18

Does the keys operate?
No
Power ON
1 Do not only START key and
EZ-ON key operate? Door
should be closed?
Yes
2 Is there beep sound in
continuity test between the
ends of latch board?
Secondary Switch (Door
should be closed)
Yes
Check PWB
No
Go to No.5 of
this flow chart.
Adjust latch
No
board (Refer to
9-1, 9-2)
-18-
3 When the door is opened, Is
the voltage of door sensing
part over 4V?
(Pin 1 to Pin 3 of CN4)
Yes
4 Is the connector connected
to MAIN PCB assembly
disconnected or
disassembled? (CN3)
No
5
Replace the Door PCB.
EBR64419501
Replace the Keypad if
changing the door PCB
doesn't resolve the problem
Replace the
No
PCB
(EBR64419604)
Reconnect or
Yes
repair
the connector.