LG DK763X, Service Manual

Page: 38 / 51

3-27 3-28
CIRCUIT DIAGRAMS
1. POWER(SMPS) CIRCUIT DIAGRAM
IMPORTANT SAFETY NOTICE
WHEN SERVICING THIS CHASSIS, UNDER NO CIR-
CUMSTANCES SHOULD THE ORIGINAL DESIGN BE
MODIFIED OR ALTERED WITHOUT PERMISSION
FROM THE LG ELECTRONICS CORPORATION. ALL
COMPONENTS SHOULD BE REPLACED ONLY WITH
TYPES IDENTICAL TO THOSE IN THE ORIGINAL CIR-
CUIT. SPECIAL COMPONENTS ARE SHADED ON THE
SCHEMATIC FOR EASY IDENTIFICATION.
THIS CIRCUIT DIAGRAM MAY OCCASIONALLY DIF-
FER FROM THE ACTUAL CIRCUIT USED. THIS WAY,
IMPLEMENTATION OF THE LATEST SAFETY AND
PERFORMANCE IMPROVEMENT CHANGES INTO
THE SET IS NOT DELAYED UNTIL THE NEW SERVICE
LITERATURE IS PRINTED.
NOTE :
1. Shaded( ) parts are critical for safety. Replace only
with specified part number.
2. Voltages are DC-measured with a digital voltmeter
during Play mode.
A B C D E F G H I J K L M N O P Q R S T
14VA No Power
D125 is Defective
12V No Power
Q123 is Defective
5.0V No Power
Q126 is Defective
5.6V No Power
Q125 is Defective
3.3V No Power
Q121 is Defective
3.3VA No Power
D121 or D122 are Defective
Switching Error
IC102,IC103 are Defective
Switching Error
IC101is Defective
No Power
FR101 is Defective
No Power
D105~D108 is Defective
5.6VA No Power
D123 is Defective
NOTES) Symbol denotes AC ground.
NOTES) Symbol denotes DC chassis ground.
NOTE) Warning
NOTE) Parts that are shaded are critical
NOTE) With respect to risk of fire or
NOTE) electricial shock.