LG CM2630B, Service Manual

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3-1
SECTION 3 ELECTRICAL
CONTENTS
ONE POINT REPAIR GUIDE ............................................................................................................................ 3-2
1. NO POWER PROBLEM ......................................................................................................................... 3-2
2. SPEAKER NO AUDIO OUTPUT ............................................................................................................ 3-3
3. USB NO OUTPUT .................................................................................................................................. 3-4
4. NO BOOTING ......................................................................................................................................... 3-5
ELECTRICAL TROUBLESHOOTING GUIDE ................................................................................................... 3-6
1. POWER (SMPS) ..................................................................................................................................... 3-6
2. μ -COM PART CHECK-1 ......................................................................................................................... 3-7
3. μ -COM PART CHECK-2 ......................................................................................................................... 3-7
4. FLD DISPLAY CHECK ........................................................................................................................... 3-8
5. TOUCH PART CHECK ........................................................................................................................... 3-9
6. AMP PART CHECK .............................................................................................................................. 3-10
7. TUNER FUNCTION CHECK................................................................................................................. 3-11
8. DAB FUNCTION CHECK (OPTIONAL) ................................................................................................ 3-12
9. BLUETOOTH FUNCTION CHECK (OPTIONAL) ................................................................................. 3-12
10. USB FUNCTION CHECK ...................................................................................................................... 3-13
11. CD FUNCTION CHECK ........................................................................................................................ 3-14
WAVEFORMS .................................................................................................................................................. 3-15
1. SERVO .................................................................................................................................................. 3-15
2. MOTOR DRIVE ..................................................................................................................................... 3-16
3. AUDIO PATH ........................................................................................................................................ 3-17
4. ADC ....................................................................................................................................................... 3-19
5. USB ....................................................................................................................................................... 3-20
6. CRYSTAL .............................................................................................................................................. 3-21
WIRING DIAGRAM .......................................................................................................................................... 3-23
BLOCK DIAGRAM .......................................................................................................................................... 3-25
CIRCUIT DIAGRAMS ...................................................................................................................................... 3-27
1. SMPS CIRCUIT DIAGRAM .................................................................................................................. 3-27
2. MAIN - MICOM CIRCUIT DIAGRAM .................................................................................................... 3-29
3. MAIN - MPEG CIRCUIT DIAGRAM ...................................................................................................... 3-31
4. MAIN - RF SERVO CIRCUIT DIAGRAM .............................................................................................. 3-33
5. MAIN - I/O & ADC CIRCUIT DIAGRAM ............................................................................................... 3-35
6. MAIN - PWM & AMP CIRCUIT DIAGRAM ........................................................................................... 3-37
7. MAIN - DC/DC CIRCUIT DIAGRAM ..................................................................................................... 3-39
8. VFD CIRCUIT DIAGRAM...................................................................................................................... 3-41
9. TOUCH CIRCUIT DIAGRAM ................................................................................................................ 3-43
10. TOP JACK CIRCUIT DIAGRAM ........................................................................................................... 3-45
CIRCUIT VOLTAGE CHART ........................................................................................................................... 3-47
1. ICs ......................................................................................................................................................... 3-47
2. CAPACITORS ....................................................................................................................................... 3-49
3. CONNECTORS ..................................................................................................................................... 3-50
PRINTED CIRCUIT BOARD DIAGRAMS ....................................................................................................... 3-51
1. SMPS P.C.BOARD ............................................................................................................................... 3-51
2. MAIN P.C.BOARD ................................................................................................................................ 3-53
3. VFD/ TOUCH/ TOP JACK P.C.BOARD ............................................................................................... 3-57