LG LRG3091ST Service Manual page 81

CHECKING FLOW CHART BY FAILURE
No key input
Key does not input
Check the oven lock operation.
Nomal: unlock
Normal?
Yes
Check the control panel and
Find the mechanical malfunction of key
Normal?
Yes
Replace the main PCB
END
No
(press the start key for three seconds)
No
10-21
Cancel the Door locking
No
Normal?
Yes
END
Replace the control panel
END