LG FLATRON L2320A - TROUBLESHOOTING GUIDE; OUT OF ORDER ON POWER

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Copyright 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
TROUBLESHOOTING GUIDE
1. OUT OF ORDER ON POWER
Check Ctrl signal
‘PCB-PWR’
NO POWER
(POWER INDICATOR OFF)
Replace
the Power B’d
Check Stand-by
5V on Power B’d
Check
Connector or
5V Output
On Power B’d
Check
18.5V Output
On Power B’d
Fail
Fail
Fail
Replace
the Power B’d
Fail
Check
Reset signal for U43
(AV B’d :
U801 Pin#8)
Check
DC/DC Converter
Output
Check Device
AV B’d
:U803,U804,U805
Bridge B’d : U905
Fail
Check I2C Line
NCTL & PCTL
Level : >4V
Check Device
Main B’d :
U3,U4,U43,U44,U12
AV B’d : U702
Bridge B’d : U904
Key-control B’d : U1,U2
Check Device
Main B’d :
U3,U4,U43,U44,U12
AV B’d : U601,U302
Audio B’d : U3
*Check the PND
Cable connection
*Check the B’d to B’d
connection
Fail
Pass
Pass
Pass
Pass
Pass
Pass
Pass
Check Point
(U43 Pin2, 3, 4, 5 )
Trouble
on NCTL
Trouble
on PCTL