LG 3854R14325A PSU Schematic

3-25

2. Power(SMPS) Block Diagram

5V_A

-29VA

VF+

RECTIFIER

LINE FILTER

SWITCHING IC

TRANS

FEED B.

REG(8V)

5.2VA

VF-

RECTIFIER(FLD)

RECTIFIER(9V)

RECTIFIER(5.2V)

LPF

RECTIFIER(14V) LPF

12V

AC90~240V

PWR ON/OFF

REG(3.3V)

3.3V/3.3V_M

REG(12V)

ON/OFF

RECTIFIER(3.8V) LPF

LOEWE

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CIRCUIT DIAGRAMS

1. POWER(SMPS) CIRCUIT DIAGRAM

IMPORTANT SAFETY NOTICE

WHEN SERVICING THIS CHASSIS, UNDER NO CIRCUMSTANCES SHOULD THE ORIGINAL DESIGN BE MODIFIED OR ALTERED WITHOUT PERMISSION FROM THE LOEWE CORPORATION. ALL COMPONENTS SHOULD BE REPLACED ONLY WITH TYPES IDENTICAL TO THOSE IN THE ORIGINAL CIRCUIT.

SPECIAL COMPONENTS ARE SHADED ON THE SCHEMATIC FOR EASY IDENTIFICATION.

THIS CIRCUIT DIAGRAM MAY OCCASIONALLY DIFFER 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.

VF(+) Power Dead. F102 is defective.

VF(-) Power Dead. ZD101 is defective.

12V Power Dead. IC103 is defective.

Power Dead. IC101 is defective.

8V Power Dead. IC105 is defective.

3.3V Power Dead. IC106 is defective.

5V Power Dead. Q107 is defective.

NOTES) Warning

NOTES) Parts that are shaded are critical NOTES) With respect to risk of fire or NOTES) electricial shock.

NOTES : Symbol denotes AC ground.

Symbol denotes DC chassis ground.