LG S55A3-D Service Manual

3-1
SECTION 3
ELECTRICAL
CONTENTS
ONE POINT REPAIR GUIDE ............................................................................................................................ 3-2
1. NO POWER PROBLEM (PVDD) ............................................................................................................ 3-2
2. POWER ON ERROR .............................................................................................................................. 3-3
3. NO SOUND (PORTABLE FUNCTION) .................................................................................................. 3-4
4. NO WIRELESS ....................................................................................................................................... 3-5
5. NO BLUETOOTH .................................................................................................................................... 3-6
6. NO SOUND (OPTICAL) .......................................................................................................................... 3-7
7. D(DC) PROTECTION ............................................................................................................................. 3-8
8. S(SHUT DOWN) PROTECTION............................................................................................................. 3-9
9. B(BURNT) PROTECTION .................................................................................................................... 3-10
WAVEFORMS OF MAJOR CHECK POINT .................................................................................................... 3-11
1. CRYSTAL .............................................................................................................................................. 3-11
2. FLASH MEMORY ................................................................................................................................. 3-12
3. TACT KEY ............................................................................................................................................. 3-13
4. USB ....................................................................................................................................................... 3-14
5. REMOTE CONTROL ............................................................................................................................ 3-15
6. OPTICAL ............................................................................................................................................... 3-16
7. PORTABLE ........................................................................................................................................... 3-17
8. AUDIO PWM ......................................................................................................................................... 3-18
9. AUDIO AMP .......................................................................................................................................... 3-20
WIRING DIAGRAM .......................................................................................................................................... 3-21
BLOCK DIAGRAMS ........................................................................................................................................ 3-23
1. SYSTEM BLOCK DIAGRAM ................................................................................................................ 3-23
2. POWER BLOCK DIAGRAM ................................................................................................................. 3-25
CIRCUIT DIAGRAMS ...................................................................................................................................... 3-27
1. SMPS CIRCUIT DIAGRAM .................................................................................................................. 3-27
2. MAIN - DSP CIRCUIT DIAGRAM ......................................................................................................... 3-29
3. MAIN - INTERFACE CIRCUIT DIAGRAM ............................................................................................ 3-31
4. MAIN - PWM & AMP CIRCUIT DIAGRAM ........................................................................................... 3-33
5. MAIN - POWER CIRCUIT DIAGRAM ................................................................................................... 3-35
6. FRONT CIRCUIT DIAGRAM ................................................................................................................ 3-37
CIRCUIT VOLTAGE CHART ........................................................................................................................... 3-39
1. ICs ......................................................................................................................................................... 3-39
2. CONNECTORS ..................................................................................................................................... 3-41
PRINTED CIRCUIT BOARD DIAGRAMS ....................................................................................................... 3-43
1. SMPS P. C. BOARD DIAGRAM ........................................................................................................... 3-43
2. MAIN P. C. BOARD DIAGRAM ............................................................................................................ 3-45
3. FRONT P. C. BOARD DIAGRAM ......................................................................................................... 3-47

LG S55A3-D Specifications

General

Brand	LG
Model	S55A3-D
Category	Speaker System
Language	English