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3-8
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
No 1.8V
There is 1,8V at IC155 Pin 2, 4
Is the Vcc (3.3V)
supplied to Pin 3 IC155?
Check 3.3V power supply
YES
YES
NO
IC155 defect
NO
No 1.25V
Check the IC154 and replace
Is there about 5.3V at
the IC154 Pin 2?
Check 5.3VA on SMPS board
YES
YES
NO
Is there about 4V ~ 5V at
the IC154 Pin 5?
Check the “PWR CTL H”
signal from µ-COM
YES
NO