LG CMS2521F Service Manual

SECTION 3
ELECTRICAL
CONTENTS
ELECTRICAL TROUBLESHOOTING GUIDE .................................................................................... 3-2
1. SMPS PART ........................................................................................................................................... 3-2
2. MUTE CIRCUIT ...................................................................................................................................... 3-4
3. AMP ABNORMAL ................................................................................................................................... 3-5
4. FUNCTION MODE AUDIO ABNORMAL ................................................................................................ 3-6
5. CD PART ................................................................................................................................................ 3-7
6. CD READING CHECK............................................................................................................................ 3-8
7. USB PART .............................................................................................................................................. 3-9
8. LCD DISPLAY CHECK ......................................................................................................................... 3-10
9. IPOD PART .......................................................................................................................................... 3-11
WAVEFORMS ............................................................................................................................................. 3-12
1. CD SEARCHING WAVEFORM ............................................................................................................ 3-12
2. SPINDLE DRIVE & MOTOR WAVEFORM .......................................................................................... 3-12
3. CD PLAYING WAVEFORM .................................................................................................................. 3-13
4. CD STOP ACTION WAVEFORM ......................................................................................................... 3-14
5. CD READING WAVEFORM ................................................................................................................. 3-14
6. CD PLAYING RF WAVEFORM ............................................................................................................ 3-15
7. USB OPERATING WAVEFORM .......................................................................................................... 3-16
8. RADIO OPERATING WAVEFORM ...................................................................................................... 3-16
WIRING DIAGRAM ................................................................................................................................... 3-17
BLOCK DIAGRAM .................................................................................................................................... 3-19
CIRCUIT DIAGRAMS ............................................................................................................................... 3-21
1. SMPS CIRCUIT DIAGRAM .................................................................................................................. 3-21
2. MAIN - MCU CIRCUIT DIAGRAM ........................................................................................................ 3-23
3. MAIN - DSP CIRCUIT DIAGRAM ......................................................................................................... 3-25
4. MAIN - SERVO CIRCUIT DIAGRAM ................................................................................................... 3-27
5. MAIN - AMP CIRCUIT DIAGRAM ........................................................................................................ 3-29
6. MAIN - D/A CIRCUIT DIAGRAM .......................................................................................................... 3-31
7. MAIN - TUNER CIRCUIT DIAGRAM .................................................................................................... 3-33
8. DISPLAY CIRCUIT DIAGRAM ............................................................................................................. 3-35
9. IPOD CIRCUIT DIAGRAM .................................................................................................................... 3-37
CIRCUIT VOLTAGE CHART ................................................................................................................. 3-39
PRINTED CIRCUIT BOARD DIAGRAMS ......................................................................................... 3-45
1. SMPS P.C.BOARD ............................................................................................................................... 3-45
2. MAIN P.C.BOARD ................................................................................................................................ 3-47
3. DISPLAY P.C.BOARD .......................................................................................................................... 3-49
4. USB P.C.BOARD .................................................................................................................................. 3-49
5. IPOD P.C.BOARD ................................................................................................................................ 3-50
3-1

LG CMS2521F Specifications

General

Brand	LG
Model	CMS2521F
Category	Stereo System
Language	English