Power Failed(Dead), No Display - LG LSRG309ST Service Manual

CHECKING FLOW CHART BY FAILURE
Power Failed(Dead),
No display?
Yes
Power On State
1
Check the key beep. Touch
the "clear key", Is the beep
sound?
No
Power Off State
2
Is the connector connected
to Power PCB disconnected
or disassembled? (CN1),
between Power PCB (CN10)
and display PCB(CN9)
CN1
CN1 CN1 CN1 CN1 CN1 CN1
CN1 CN1 CN1 CN1 CN1 CN1
CN1 CN1 CN1 CN1 CN1 CN1
CN1 CN1 CN1
CN9 CN9 CN9 CN9 CN9 CN9 CN9
CN9 CN9 CN9 CN9 CN9 CN9
CN9 CN9 CN9 CN9
CN9 CN9 CN9 CN9 CN9
CN10
CN10 CN10 CN10 CN10 CN10 CN10
CN10 CN10 CN10 CN10 CN10 CN10
CN10 CN10 CN10 CN10 CN10 CN10
CN10 CN10 CN10
No
Yes
Go to No 4
Reconnect or
Yes
repair the
connector
10-2
Power Off
3
Is the electric wiring normal?
Measure the resistance
Power cord and CN01's
connection
Normal : continuity
Abnormal : infinite
- Code L to Pin3 of CN01(BK)
- Code N to Pin1 of CN01(WH)
BK color is L.
L L L L L L L L L L L L L L L L L
L
White color is N
Yes
Replace the
No
defective
harness
Normal Abnormal
Continuity Infinite
N N N N N N N N N N N N N N N N N
N