LG LHB675FB Service Manual page 16

DIGITAL DISPLAY & MEDIA TRAINING MASTER ......................................................................................... 2-2
1. DISTORTED PICTURE ........................................................................................................................... 2-2
2. NO PICTURE .......................................................................................................................................... 2-7
3. PICTURE COLOR ................................................................................................................................. 2-12
4. NOISE/AUDIO PROBLEMS .................................................................................................................. 2-14
5. MISCELLANEOUS ................................................................................................................................ 2-17
6. BLU-RAY PLAYER ............................................................................................................................... 2-26
ONE POINT REPAIR GUIDE .......................................................................................................................... 2-27
1. NO POWER PROBLEM ....................................................................................................................... 2-27
2. NO BOOTING WHEN YOU TURN THE UNIT ON, NO MESSAGE ON FRONT PANEL.................... 2-29
3. WIRED NETWORK CONNECTION ERROR ....................................................................................... 2-36
4. BAD HDMI VIDEO / AUDIO OUTPUT .................................................................................................. 2-37
5. NO AUDIO FROM SPEAKER ............................................................................................................... 2-38
6. NO USB ................................................................................................................................................ 2-39
7. BT CONNECTION ERROR .................................................................................................................. 2-40
ELECTRICAL TROUBLESHOOTING GUIDE ................................................................................................. 2-41
1. SYSTEM POWER SUPPLY ON SMPS BOARD .................................................................................. 2-41
2. POWER SUPPLY ON MAIN BOARD ................................................................................................... 2-44
3. SYSTEM PART ..................................................................................................................................... 2-48
4. NO HDMI OUTPUT ............................................................................................................................... 2-50
5. NO AUDIO OUTPUT ............................................................................................................................ 2-51
WAVEFORMS .................................................................................................................................................. 2-52
1. SYSTEM PART - 1 (MPEG CRYSTAL 27 MHz) .................................................................................. 2-52
2. SYSTEM PART - 2 (DDR3 MEMORY) ................................................................................................. 2-53
3. AUDIO PART - 1 (ADC I2C) ................................................................................................................. 2-54
4. AUDIO PART - 2 (PWM I2S / I2C) ....................................................................................................... 2-55
5. HDMI PART .......................................................................................................................................... 2-56
WIRING DIAGRAM .......................................................................................................................................... 2-57
BLOCK DIAGRAM .......................................................................................................................................... 2-59
CIRCUIT DIAGRAMS ...................................................................................................................................... 2-61
1. SMPS CIRCUIT DIAGRAM .................................................................................................................. 2-61
2. MAIN & AMP - MICOM CIRCUIT DIAGRAM........................................................................................ 2-63
3. MAIN & AMP - POWER CIRCUIT DIAGRAM ...................................................................................... 2-65
4. MAIN & AMP - MPEG CIRCUIT DIAGRAM ......................................................................................... 2-67
5. MAIN & AMP - MEMORY CIRCUIT DIAGRAM .................................................................................... 2-69
6. MAIN & AMP - F/E CIRCUIT DIAGRAM .............................................................................................. 2-71
7. MAIN & AMP - ADC / MIC CIRCUIT DIAGRAM................................................................................... 2-79
8. MAIN & AMP - I/O CIRCUIT DIAGRAM ............................................................................................... 2-75
9. MAIN & AMP - PWM CIRCUIT DIAGRAM ........................................................................................... 2-77
10. MAIN & AMP - AMP CIRCUIT DIAGRAM ............................................................................................ 2-79
11. JACK CIRCUIT DIAGRAM (OPTIONAL PART) ................................................................................... 2-81
12. FRONT CIRCUIT DIAGRAM ................................................................................................................ 2-85
CIRCUIT VOLTAGE CHART ........................................................................................................................... 2-87
1. ICs ......................................................................................................................................................... 2-87
2. CAPACITORS ....................................................................................................................................... 2-88
3. CONNECTORS ..................................................................................................................................... 2-88
PRINTED CIRCUIT BOARD DIAGRAMS ....................................................................................................... 2-89
1. SMPS P. C. BOARD ............................................................................................................................. 2-89
2. MAIN & AMP P. C. BOARD .................................................................................................................. 2-91
3. JACK P. C. BOARD (OPTIONAL PART) .............................................................................................. 2-93
4. FRONT P. C. BOARD ........................................................................................................................... 2-95
SECTION 2 ELECTRICAL
CONTENTS
2-1