LG LAC2900N, Service Manual

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1-1
CONTENTS
SECTION 1 SUMMARY
SERVICING PRECAUTIONS .............................................................................................................................1-2
ESD PRECAUTIONS ..........................................................................................................................................1-3
SPECIFICATIONS ..............................................................................................................................................1-4
FIRMWARE UPGRADE METHOD .....................................................................................................................1-5
HOW TO CONNECT AUDIO SET TO POWER SUPPLY ..................................................................................1-6
SECTION 2 ELECTRICAL
ELECTRICAL TROUBLESHOOTING GUIDE & WAVEFORMS .......................................................................2-1
1. SYSTEM CONTROL ERROR CORRECTION FLOW CHART .................................................................2-1
2. SOUND ERROR CORRECTION FLOW CHART ......................................................................................2-2
3. DISPLAY ERROR CORRECTION FLOW CHART ....................................................................................2-6
4. TUNER ERROR CORRECTION FLOW CHART .......................................................................................2-9
5. CDP ERROR CORRECTION FLOW CHART .........................................................................................2-11
6. AUX ERROR CORRECTION FLOW CHART ..........................................................................................2-14
• WAVEFORMS ...........................................................................................................................................2-15
• CIRCUIT VOLTAGE CHART ....................................................................................................................2-17
INTERNAL BLOCK DIAGRAM OF ICs ...........................................................................................................2-18
1. IC301 (HA13173AH) ................................................................................................................................2-20
2. IC402 (
μ PDD78F1164) ............................................................................................................................2-23
3. IC503 (LC786923W) ................................................................................................................................2-28
4. IC504 (AM5810) .......................................................................................................................................2-30
5. IC801 (TB2946HQ) ..................................................................................................................................2-31
6. IC802 (BD3702FV) ...................................................................................................................................2-37
7. IC901 (MC5502) .......................................................................................................................................2-32
WIRING DIAGRAM ...........................................................................................................................................2-35
BLOCK DIAGRAM ...........................................................................................................................................2-37
CIRCUIT DIAGRAMS .......................................................................................................................................2-39
1. MAIN CIRCUIT DIAGRAM .......................................................................................................................2-39
2. FRONT CIRCUIT DIAGRAM ...................................................................................................................2-41
3. CDP CIRCUIT DIAGRAM ........................................................................................................................2-43
PRINTED CIRCUIT BOARD DIAGRAMS ........................................................................................................2-45
1. MAIN P.C.BOARD ...................................................................................................................................2-45
2. FRONT P.C.BOARD ................................................................................................................................2-47
3. CDP P.C.BOARD .....................................................................................................................................2-49
SECTION 3 EXPLODED VIEWS
1. CABINET AND MAIN FRAME SECTION ..................................................................................................3-1
2. MECHANISM(PICK-UP) SECTION ...........................................................................................................3-3
SECTION 4 REPLACEMENT PARTS LIST