Circuit Diagrams; Power(Smps) Circuit Diagram - LG LGXBR342 Service Manual

CIRCUIT DIAGRAMS

1. POWER(SMPS) CIRCUIT DIAGRAM

No power.
BD101,TH01 is Defective
S/W Error
IC101,IC104 is Defective
No Power
F101 is Defective
NOTE) Warning
NOTES) Symbol denotes AC ground.
NOTE) Parts that are shaded are critical
NOTE) With respect to risk of fire or
NOTES) Symbol denotes DC chassis ground.
NOTE) electricial shock.
-29VA No Power
D127 is Defective
No Power
D102 is Defective
12V No Power
D126 is Defective
5.3VA No Power
D121 is Defective
30VA No Power
D130 is Defective
Switching Error
IC105,IC106 are Defective
5V No Power
D124 is Defective
No Power
D104 is Defective
Switching Error
IC105,IC106 are Defective
3.3V No Power
D122 is Defective
3-34
IMPORTANT SAFETY NOTICE
WHEN SERVICING THIS CHASSIS, UNDER NO CIR-
CUMSTANCES SHOULD THE ORIGINAL DESIGN BE
MODIFIED OR ALTERED WITHOUT PERMISSION
FROM THE ZENITH ELECTRONICS CORPORATION.
ALL COMPONENTS SHOULD BE REPLACED ONLY
WITH TYPES IDENTICAL TO THOSE IN THE ORIGI-
No Digitron Displayed
D128,R107,ZD151 are Defective
28V No Power
Q120 or ZD153 are Defective
28V No Power
D129 is Defective
12V No Power
D125 is Defective
12V No Power
IC157 is Defective
1.8V No Power
D123 is Defective
5V No Power
IC151 is Defective
3.3V No Power
IC154 is Defective
3-35
NAL CIRCUIT. SPECIAL COMPONENTS ARE SHADED NOTE :
ON THE SCHEMATIC FOR EASY IDENTIFICATION. 1. Shaded( ) parts are critical for safety. Replace only
THIS CIRCUIT DIAGRAM MAY OCCASIONALLY DIF- with specified part number.
FER FROM THE ACTUAL CIRCUIT USED. THIS WAY, 2. Voltages are DC-measured with a digital voltmeter
IMPLEMENTATION OF THE LATEST SAFETY AND during Play mode.
PERFORMANCE IMPROVEMENT CHANGES INTO
THE SET IS NOT DELAYED UNTIL THE NEW SERVICE
LITERATURE IS PRINTED.
-12V No Power
ZD103 is Defective
2.5V No Power
D153 is Defective
1.8V No Power
IC160 is Defective