LG MDS902S, Service Manual

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1-1
CONTENTS
SECTION 1
GENERAL
SERVICING PRECAUTIONS ......................................1-2
• NOTES REGARDING HANDLING OF THE PICK-UP
• NOTES REGARDING COMPACT DISC PLAYER REPAIRS
ESD PRECAUTIONS ...................................................1-4
LOCATION OF USERS CONTROLS .........................1-5
SPECIFICATIONS ........................................................1-7
SECTION 2
EXPLODED VIEWS
CABINET AND MAIN FRAME SECTION ..................2-1
TAPE DECK MECHANISM EXPLODED VIEW ........2-3
1. TAPE DECK MECHANISM
(A/R & A/S : LEFT A/R DECK) ..........................2-3
2. TAPE DECK MECHANISM
(A/R & A/S : RIGHT A/S DECK).........................2-5
DVD MECHANISM EXPLODED VIEW ......................2-7
SPEAKER EXPLODED VIEW ....................................2-9
1. MODEL : MDS902V (FRONT SPEAKERS) ....2-9
2. MODEL : MDS902S (REAR SPEAKERS) .....2-11
3. MODEL : MDS902W (SUBWOOFER)...........2-13
PACKING ACCESSORY SECTION .........................2-17
SECTION 3
AUDIO PART ELECTRICAL
ELECTRICAL TROUBLESHOOTING GUIDE ...........3-1
1. POWER (SMPS) ................................................3-1
2. P-SENS...............................................................3-2
3. VKK CHECK.......................................................3-2
4. MICOM (IC302) CHANGE.................................3-3
5. P-CTRL CHECK.................................................3-3
6. MUTING TROUBLESHOOTING (MUTE STATE) .......3-4
7. EXPEND IC (IC501 / 502) STATE ....................3-4
8. FUNCTION MODE HAS NO SOUND
(NJW1190) IC601................................................3-5
9. IC601 (NJW1190) TROUBLUSHOOTING .......3-9
10. AMP MODULE TROUBLESHOOTING..........3-10
11. REC CHECK
(Q201, Q202 ON : R276, R226 HIGH) ...........3-11
12. DUBBING CHECK
("NORMAL OR REC" // "HIGH")......................3-12
INTERNAL BLOCK DIAGRAM OF ICs ...................3-13
1. HA12237F.........................................................3-13
2. NJW1190 ..........................................................3-14
3. AF330W20FT ...................................................3-14
4. AF350W01FT ...................................................3-16
WIRING DIAGRAM ....................................................3-18
BLOCK DIAGRAM .....................................................3-20
SCHEMATIC DIAGRAMS .........................................3-22
1. SMPS (POWER) SCHEMATIC DIAGRAM ....3-22
2. SUB SMPS (POWER) SCHEMATIC DIAGRAM....3-24
3. AUDIO MAIN SCHEMATIC DIAGRAM ..........3-26
4. DECK SCHEMATIC DIAGRAM......................3-28
5. USB, AUX2 & HEADPHONE AMP
SCHEMATIC DIAGRAM .................................3-30
6. I/O JACK SCHEMATIC DIAGRAM.................3-32
7. AMP SCHEMATIC DIAGRAM.........................3-34
8. WOOFER AMP SCHEMATIC DIAGRAM ......3-36
9. FRONT SCHEMATIC DIAGRAM ...................3-38
PRINTED CIRCUIT DIAGRAMS ...............................3-40
1. MAIN P.C.BOARD............................................3-40
2. SMPS (POWER) P.C.BOARD ........................3-44
3. SUB SMPS (POWER) P.C.BOARD ...............3-45
4. FRONT P.C.BOARD ........................................3-46
5. AMP P.C.BOARD .............................................3-50
6. WOOFER AMP P.C.BOARD...........................3-52
SECTION 4
DVD PART ELECTRICAL
ELECTRICAL TROUBLESHOOTING GUIDE ...........4-1
1. POWER...............................................................4-1
2. TEST & DEBUG.................................................4-2
3. USB .....................................................................4-7
WAVEFORMS ...............................................................4-8
1. WHEN POWER ON,
RESET & DATA ETC WAVEFORM...................4-8
2. OPEN / CLOSE WAVEFORM AT POWER ON .......4-9
3. STARTING ACTION WAVEFORM IN MD DEVICE......4-9
4. FOCUS WAVEFORM (AT CD).........................4-10
5. FOCUS WAVEFORM (AT DVD) ......................4-10
6. AT POWER ON, SPINDLE SIGNAL AT MD DECK ........4-11
7. AT FIRST ACTION, FOCUS SIGNAL A, B, C, D ....4-11
8. TRACKING SIGNAL..........................................4-12
9. RF WAVEFORM................................................4-12
10. DISK TYPE JUGEMENT WAVEFORM...........4-13
SCHEMATIC DIAGRAMS .........................................4-15
1. MPEG SCHEMATIC DIAGRAM .....................4-15
2. SERVO SCHEMATIC DIAGRAM ...................4-17
3. USB SCHEMATIC DIAGRAM.........................4-19
4. INTERFACE SCHEMATIC DIAGRAM ...........4-21
PRINTED CIRCUIT DIAGRAM .................................4-23
DVD P.C.BOARD .................................................4-23
SECTION 5
REPLACEMENT PARTS LIST
........5-1