LG CMS9540F Service Manual

SECTION 3
ELECTRICAL
CONTENTS
ONE POINT REPAIR GUIDE ............................................................................................................................ 3-2
1. NO POWER ............................................................................................................................................ 3-2
2. NO BOOTING WHEN POWER ON THE SET ....................................................................................... 3-4
3. VFD IS NOT DISPLAYED WHEN POWER ON THE SET ..................................................................... 3-5
4. NO BOOTING IN CD/USB FUNCTION .................................................................................................. 3-6
5. NO OPERATION OF MD (DRIVING THE SERVO MOTORS) ............................................................ 3-11
6. NO SOUND .......................................................................................................................................... 3-16
7. AUDIO OUTPUT IS SMALL OR NO AUDIO OUTPUT ........................................................................ 3-22
8. NO POWER ON (STANDBY LED IS BLINKING) ................................................................................ 3-23
9. SPEAKER NO AUDIO .......................................................................................................................... 3-24
ELECTRICAL TROUBLESHOOTING GUIDE ................................................................................................ 3-25
1. POWER SUPPLY ON SMPS BOARD ................................................................................................. 3-25
2. SYSTEM PART .................................................................................................................................... 3-29
3. NO AUDIO PART ................................................................................................................................. 3-30
4. NO LIGHTING (WOOFER SPEAKER) ................................................................................................. 3-35
WAVEFORMS OF MAJOR CHECK POINT ................................................................................................... 3-36
WIRING DIAGRAM ......................................................................................................................................... 3-41
BLOCK DIAGRAMS ........................................................................................................................................ 3-43
1. SMPS BLOCK DIAGRAM..................................................................................................................... 3-43
2. MAIN SYSTEM BLOCK DIAGRAM ...................................................................................................... 3-45
3. MAIN POWER BLOCK DIAGRAM ....................................................................................................... 3-47
CIRCUIT DIAGRAMS ...................................................................................................................................... 3-49
1. SMPS - POWER #1 CIRCUIT DIAGRAM ............................................................................................ 3-49
2. SMPS - POWER #2 CIRCUIT DIAGRAM ............................................................................................ 3-51
3. MAIN - CD DSP CIRCUIT DIAGRAM .................................................................................................. 3-53
4. MAIN - RF / SERVO CIRCUIT DIAGRAM ........................................................................................... 3-55
5. MAIN - ADC / PWM CIRCUIT DIAGRAM ............................................................................................ 3-57
6. MAIN - AMP CIRCUIT DIAGRAM ........................................................................................................ 3-59
7. FRONT VOLUME CIRCUIT DIAGRAM ................................................................................................ 3-61
8. MIC & PORTABLE CIRCUIT DIAGRAM .............................................................................................. 3-63
9. FRONT SPEAKER MAIN CIRCUIT DIAGRAM .................................................................................... 3-65
10. FRONT SPEAKER SUB CIRCUIT DIAGRAM ..................................................................................... 3-67
11. WOOFER SPEAKER MAIN CIRCUIT DIAGRAM ................................................................................ 3-69
12. WOOFER SPEAKER SUB CIRCUIT DIAGRAM .................................................................................. 3-71
CIRCUIT VOLTAGE CHART .......................................................................................................................... 3-73
1. CONNECTORS .................................................................................................................................... 3-73
2. CAPACITORS....................................................................................................................................... 3-74
PRINTED CIRCUIT BOARD DIAGRAMS ....................................................................................................... 3-75
1. SMPS P.C.BOARD ............................................................................................................................... 3-75
2. MAIN P.C.BOARD ................................................................................................................................ 3-79
3. FRONT VOLUME P.C.BOARD ............................................................................................................ 3-83
4. MIC & PORTABLE P.C.BOARD ........................................................................................................... 3-85
5. FRONT SPEAKER MAIN P.C.BOARD ................................................................................................ 3-85
6. FRONT SPEAKER SUB P.C.BOARD .................................................................................................. 3-85
7. WOOFER SPEAKER MAIN P.C.BOARD ............................................................................................. 3-87
8. WOOFER SPEAKER SUB P.C.BOARD .............................................................................................. 3-87
3-1

LG CMS9540F Specifications

General

Brand	LG
Model	CMS9540F
Category	Stereo System
Language	English