Main Part; Main Electrical Troubleshooting Guide; Power (Dc-Dc Converter) Circuit - LG DP381B Service Manual

MAIN ELECTRICAL TROUBLESHOOTING GUIDE

1. POWER (DC-DC CONVERTER) CIRCUIT

A. POWER
No power on
by ADAPTOR
YES
NO
Is ADAPTOR
out 9V
YES
NO
Is F1 OK.
YES
A
A
YES
No +1.8V
YES
NO
Is U4
3.3V OK?
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Only for training and service purposes

MAIN PART

Replace ADAPTOR
Replace F1
No +3.3V
Replace U4
No power on
by BATTERY
YES
Is
BATTERY
OK?
YES
A
No +5V
Replace U4
3-11
NO
Replace BATTERY
No LCD power
Replace
CON1 or CON2
LGE Internal Use Only