LG CM5660 Service Manual page 18

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 ........................................................................................................................ 3-9
6. NO SOUND ........................................................................................................................................... 3-14
ELECTRICAL TROUBLESHOOTING GUIDE ................................................................................................. 3-22
1. POWER (SMPS) ................................................................................................................................... 3-22
2. MCS PART CHECK .............................................................................................................................. 3-25
3. FLD DISPLAY CHECK ......................................................................................................................... 3-26
4. PWM MODULATION CHECK ............................................................................................................... 3-27
5. POWER AMP PART CHECK ............................................................................................................... 3-28
6. TUNER / AUX FUNCTION CHECK ...................................................................................................... 3-29
7. TUNER FUNCTION CHECK................................................................................................................. 3-30
8. CD FUNCTION CHECK ........................................................................................................................ 3-31
9. DOUBLE USB FUNCTION ................................................................................................................... 3-32
WAVEFORMS OF MAJOR CHECK POINT .................................................................................................... 3-33
1. DSP (IC500) .......................................................................................................................................... 3-33
2. SDRAM (IC504) .................................................................................................................................... 3-34
3. SERVO (IC401) ..................................................................................................................................... 3-35
4. MOTOR DRIVER (IC400) ..................................................................................................................... 3-36
5. ADC (IC202) .......................................................................................................................................... 3-37
6. USB (JK500) ......................................................................................................................................... 3-37
7. BLUETOOTH (CN501) .......................................................................................................................... 3-38
WIRING DIAGRAM .......................................................................................................................................... 3-39
BLOCK DIAGRAMS ........................................................................................................................................ 3-41
1. SYSTEM BLOCK DIAGRAM ................................................................................................................ 3-41
2. POWER BLOCK DIAGRAM ................................................................................................................. 3-43
CIRCUIT DIAGRAMS ...................................................................................................................................... 3-45
1. SMPS CIRCUIT DIAGRAM .................................................................................................................. 3-46
2. MAIN - DSP SoC CIRCUIT DIAGRAM ................................................................................................. 3-47
3. MAIN - POWER PART CIRCUIT DIAGRAM ........................................................................................ 3-49
4. MAIN - ADC/DAC CIRCUIT DIAGRAM ................................................................................................ 3-51
5. MAIN - RF SERVO CIRCUIT DIAGRAM .............................................................................................. 3-53
6. MAIN - PWM/AMP IC CIRCUIT DIAGRAM .......................................................................................... 3-55
7. FRONT CIRCUIT DIAGRAM ................................................................................................................ 3-57
8. JACK CIRCUIT DIAGRAM ................................................................................................................... 3-59
CIRCUIT VOLTAGE CHART ........................................................................................................................... 3-61
1. ICs VOLTAGE ....................................................................................................................................... 3-61
2. CAPACITORS VOLTAGE ..................................................................................................................... 3-62
PRINTED CIRCUIT BOARD DIAGRAMS ....................................................................................................... 3-63
1. SMPS P.C.BOARD ............................................................................................................................... 3-63
2. MAIN P.C.BOARD ................................................................................................................................ 3-65
3. FRONT P.C.BOARD ............................................................................................................................. 3-67
4. JACK P.C.BOARD ................................................................................................................................ 3-69
SECTION 3
ELECTRICAL
CONTENTS
3-1