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3-7
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
No 3.3V
Is there
about 3.8V at the IC152
pin1?
Check D123 on SMPS
Board and Replace
YES
YES
NO
Is there
about 4V ~ 5V at the IC152
pin4?
Check the “PWR CTL H”
signal from µ-COM
YES
NO
Check the IC152 and Replace
No SW_5.3VA
Is the
VCC (5.3V) supplied to
Q158 Emiter?
Check 5.3VA on SMPS Board
YES
YES
NO
Is there about 0V
at R179 and R156?
Check the “STANBY H”
signal from µ-COM
YES
NO
Check Q158 and Replace
ELECTRICAL TROUBLESHOOTING GUIDE