LG MDV902 Service Manual
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LG MDV902 Service Manual

Karaoke mini home theater
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KARAOKE MINI
HOME THEATER
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE UNIT, READ THE "SAFETY PRECAUTIONS"
IN THIS MANUAL.
MODEL : MDV902(MDS902V, MDS902S, MDS902W)
P/NO : AFN35036903
JULY, 2007

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  • Page 1 KARAOKE MINI HOME THEATER SERVICE MANUAL CAUTION BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS” IN THIS MANUAL. MODEL : MDV902(MDS902V, MDS902S, MDS902W) P/NO : AFN35036903 JULY, 2007...

  • Page 2: Table Of Contents

    CONTENTS SECTION 1 WIRING DIAGRAM ............3-18 BLOCK DIAGRAM.............3-20 GENERAL SCHEMATIC DIAGRAMS .........3-22 SERVICING PRECAUTIONS ........1-2 1. SMPS (POWER) SCHEMATIC DIAGRAM ..3-22 • NOTES REGARDING HANDLING OF THE PICK-UP 2. SUB SMPS (POWER) SCHEMATIC DIAGRAM..3-24 • NOTES REGARDING COMPACT DISC PLAYER REPAIRS 3.

  • Page 3: Servicing Precautions

    SECTION 1 GENERAL SERVICING PRECAUTIONS NOTES REGARDING HANDLING OF THE PICK-UP 1. Notes for transport and storage 1) The pick-up should always be left in its conductive bag until immediately prior to use. 2) The pick-up should never be subjected to external pressure or impact. 2.

  • Page 4: Notes Regarding Compact Disc Player Repairs

    NOTES REGARDING COMPACT DISC PLAYER REPAIRS 1. Preparations 1) Compact disc players incorporate a great many ICs as well as the pick-up (laser diode). These components are sensitive to, and easily affected by, static electricity. If such static electricity is high voltage, components can be damaged, and for that reason components should be handled with care.

  • Page 5: Esd Precautions

    ESD PRECAUTIONS Electrostatically Sensitive Devices (ESD) Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components commonly are called electrostatically sensitive devices (ESD). Examples of typical ESD devices are integrated circuits and some field-effect transistors and semiconductor chip components. The following techniques should be used to help reduce the incidence of component damage caused by static electricity.

  • Page 6: Location Of Users Controls

    LOCATION OF USERS CONTROLS FRONT PANEL / REAR PANEL COMPONENT VIDEO OUT (PROGRESSIVE SCAN) MONITOR S-VIDEO WOOFER SYSTEM SUB WOOFER SPEAKER 1. • DISC SKIP button PUSH EJECT position (TAPE 1) • OPEN / CLOSE button PUSH EJECT position (TAPE 2) •...

  • Page 7: Remote Control

    REMOTE CONTROL 1. POWER button 2. FUNCTION SELECT buttons (TUNER / BAND, DVD / KARAOKE, AUX, USB) 3. NUMERIC buttons (0-9) 4. TAPE FUNCTION buttons • REVERSE PLAY ( ) • PLAY ( ) • REWIND / FAST FORWARD PLAY ( •...

  • Page 8: Specifications

    SPECIFICATIONS • GENERAL Power supply Refer to the main label. Power consumption 200W Net Weight 8.65kg External dimensions (W x H x D) 280 X 365 X 370 mm • TUNER/AMPLIFIER FM Tuning Range 87.5 - 108.0MHz or 65 -74MHz, 87.5 -108.0MHz Intermediate Frequency 10.7MHz Signal to Noise Ratio...
  • Page 9 MEMO...

  • Page 10: Exploded Views

    SECTION 2 EXPLODED VIEWS CABINET AND MAIN FRAME SECTION A46U SVC purchase order caution MAIN board is array coming USB & JACK board. Purchase order board separately supply incomprehensible. Supply is possible in Location No A46 state in exploded views. CABLE3 CABLE6 CABLE2...

  • Page 11: Tape Deck Mechanism Exploded View

    TAPE DECK MECHANISM EXPLODED VIEW 1. TAPE DECK MECHANISM (A/R & A/S : LEFT A/R DECK)

  • Page 12: Tape Deck Mechanism (A/R & A/S : Right A/S Deck)

    2. TAPE DECK MECHANISM (A/R & A/S : RIGHT A/S DECK)

  • Page 13: Dvd Mechanism Exploded View

    DVD MECHANISM EXPLODED VIEW 169A 169B 169C 012A 012A 012A 035A...

  • Page 14: Speaker Exploded View

    SPEAKER EXPLODED VIEW 1. MODEL : MDS902V (FRONT SPEAKERS) A80R A80BR A80L A80BL 862L 862R A80AL 850L 850R A80AR WIRE81 WIRE80 2-10...

  • Page 15: Model : Mds902S (Rear Speakers)

    2. MODEL : MDS902S (REAR SPEAKERS) A60L A60BL A60BR A60AR A60AL 650L 650R A60R WIRE60 WIRE61 2-11 2-12...

  • Page 16: Model : Mds902W (Subwoofer)

    3. MODEL : MDS902W (SUBWOOFER) A90B A90A WIRE90 WIRE91 2-13 2-14...
  • Page 17 MEMO MEMO 2-15 2-16...

  • Page 18: Packing Accessory Section

    PACKING ACCESSORY SECTION 2-17...

  • Page 19: Electrical Troubleshooting Guide

    SECTION 3 AUDIO PART ELECTRICAL ELECTRICAL TROUBLESHOOTING GUIDE 1. POWER (SMPS) CHECK AC CONNECT NO POWER LINE PATTERN THE OPEN LINE CHECK F901 FUSE REPLACE FUSE CHECK BD901 + TO LOW IMPEDANCE - PIN IMPEDANCE CHANGE ASSY CHECK C986 CHECK LINE SHORT VOLT(5.6V) CHECK CONNECTION CN902, CN903...

  • Page 20: P-Sens

    2. P-SENS P-SENS SMPS ASS'Y CN902 SMPS TROUBLESHOOTING CONSULT - -> 7PIN 5.1V CHECK MAIN PCB CN710 CN710 CONNECTION STATE CHECK 7PIN 5.1V CHECK MAIN PCB CN304 MAIN PCB PATTERN CUTTING 6PIN 5.1V CHECK AND SHORT CHECK FRONT PN304 35PIN 5.1V CHECK IC304 INPUT VOLTAGE 5V OVER STATE FRONT IC304 (RESET IC) CHECK AND OUTPUT VOLTAGE 4V...

  • Page 21: Micom (Ic302) Change

    4. MICOM (IC302) CHANGE MICOM (IC302) CHANGE P-SENS "P-SENS" TROUBLESHOOTING CHECK CONSULT "RESET" TR "Q302, Q303" Q302, Q303 IC302 10PIN CHECK CHANGE STATE CHECK ( LOW --> HIGH) IC302 VDD SMPS PN304 MAIN CN710 (19, 20, 59)PIN 34PIN +5.6V (MI) TROUBLESHOOTI 6PIN CHECK VOLTAGE...

  • Page 22: Muting Troubleshooting (Mute State)

    6. MUTING TROUBLESHOOTING (MUTE STATE) MUTING TROUBLESHOOTING (MUTE STATE) MICOM EXPEND IC (IC305) Q752 (A102) IC302 57PIN HIGH STATE CHECK Emitter "HIGH" STATE CHECK EXPEND IC (IC305) Q752 (A102) STATE CHECK FAULTY IS CHANGE Q752 (A102) FAULTY IS CHANGE Q701, Q751 (D1302) EACH PART TR CHANGE BASE "HIGH"...

  • Page 23: Function Mode Has No Sound (Njw1190) Ic601

    8. FUNCTION MODE HAS NO SOUND (NJW1190) IC601 TAPE IC201 INPUT CHECK DECK HEAD WIRE (HEAD INPUT) "A" DECK CONNECTION STATE CHECK 32, 39 "B" DECK 34, 37 IC502 10PIN IC502 2PIN / 3PIN IC201 OUTPUT (PB MUTE) STATE CHECK (DATA / CLK) CHECK (5, 26PIN) CHECK IC502 16PIN VDD CHECK...
  • Page 24 JK601 SIGNAL INPUT CHECK IC601 5, 34PIN MAIN PCB PATTERN CHECK SIGNAL INPUT CHECK IC601 (NJW1190) IC601 17, 22PIN TROUBLESHOOTING CONSULT OUTPUT SIGNAL CHECK AUX OUTPUT PN709 6, 8PIN SIGNAL CHECK and CD TROUBLESHOOTING CONSULT IC601 4, 35PIN MAIN PCB PATTERN CHECK SIGNAL INPUT CHECK IC601 (NJW1190) IC601 17, 22PIN...
  • Page 25 TUNER TU101 2PIN TU101 3/5 CN701 2PIN "+12V" CHECK "+9V" VOLTAGE SIGNAL CHECK CHECK TU101 6, 7, 8, MICOM IC302 CHECK 9PIN CHECK (PLL-CE, PLL-DI, (PIN 73, 71, 70, 72) CLK, PLL-DO) TUNER MODULE CHANGE IC601 MAIN PCB PATTERN CHECK 2, 37PIN SIGNAL INPUT CHECK IC601 17,...
  • Page 26 CN307 IC302 65PIN JK401, JK402 CHECK 5PIN "MIC-SIGNAL" MIC-SENSE CHECK CHECK IC402 JK401,JK402 4PIN OUTPUT CHECK 8PIN SIGNAL INPUT CHECK IC402 6PIN "+10.4V " CHECK IC402 7PIN SIGNAL OUTPUT CHECK IC402 2PIN SIGNAL INPUT CHECK IC402 3PIN SIGNAL OUTPUT CHECK BETWEEN DVD PCB IC408 PCB IC408 3PIN SIGNAL AND CN307 PATTERN CHECK...

  • Page 27: Ic601 (Njw1190) Troublushooting

    9. IC601 (NJW1190) TROUBLUSHOOTING IC601 (NJW1190) TROUBLUSHOOTING IC601 24PIN SMPS VOLTAGE CHECK CONSULT VOLTAGE INPUT CHECK IC601 19, 20 SDA, SCA PULSE WAVE IC302 7,7 2PIN CHECK CHECK (VOL UP, DOWN TURN CHECK) IC302 TROUBLESHOOTING FUNCTION IC601 CHANGE INPUT PORT SIGNAL CHECK (NJW1190 TROUBLESHOOTING) IC601 17, 22PIN WAVE OUTPUT CHECK IC601 OK...

  • Page 28: Amp Module Troubleshooting

    10. AMP MODULE TROUBLESHOOTING AMP MODULE TROUBLESHOOTING IC501 9PIN(AMP-PWR) EXPEND IC TROUBLESHOOTING CONSULT HIGH CHECK PN702 3PIN PROTECTION "HIGH" --> SMPS VOLTAGE "PROTECTION" CHECK AND AMP ON/OFF STATE CHECK (HIGH --> LOW) AMP MODULE CHECK : MOS FET BOTH ARE READ SHORT --> AMP DEAD IC701 11PIN "AMP-ON/OFF"...

  • Page 29: Rec Check

    11. REC CHECK (Q201, Q202 ON : R276, R226 HIGH) IC601 21PIN VOLTAGE INPUT CHECK IC601 EACH INPUT TUNER 2, 37 TAPE 3, 36 REC INPUT CHECK CD 4, 35 AUX 5, 34PIN SIGNAL INPUT CHECK IC201 7, 24PIN INPUT LINE CHECK INPUT CHECK IF NO SIGNAL, IC201 10, 21PIN...

  • Page 30: Dubbing Check ("Normal Or Rec" // "High")

    12. DUBBING CHECK ("NORMAL OR REC" // "HIGH") IC601 7, 32 OUTPUT CHECK IC601 EACH INPUT TUNER 2, 37 TAPE REC INPUT CHECK 3, 36 CD 4, 35 AUX 5, 34PIN SIGNAL INPUT CHECK IC201 7, 24PIN INPUT LINE CHECK INPUT CHECK IF NO SIGNAL, IC201 10, 21PIN...

  • Page 31: Internal Block Diagram Of Ics

    INTERNAL BLOCK DIAGRAM OF ICs 1. HA12237F BLOCK DIAGRAM 3-13...

  • Page 32: Njw1190

    2. NJW1190 BLOCK DIAGRAM 3. AF330W20FT 3-1. PIN CONFIGURATION 3-14...
  • Page 33 3-2. BLOCK DIAGRAM 3-3. PIN DESCRIPTION 3-15...

  • Page 34: Af350W01Ft

    4. AF350W01FT 4-1. PIN CONFIGURATION 4-2. BLOCK DIAGRAM 3-16...
  • Page 35 4-3. PIN DESCRIPTION 3-17...

  • Page 36: Wiring Diagram

    WIRING DIAGRAM 3-18 3-19...
  • Page 37 BLOCK DIAGRAM 3-20 3-21...

  • Page 38: Schematic Diagrams

    BE MODIFIED OR ALTERED WITHOUT PERMISSION FROM THE ACTUAL CIRCUIT USED. THIS WAY, 2. Voltages are DC-measured with a digital voltmeter FROM THE LG CORPORATION. ALL COMPONENTS IMPLEMENTATION OF THE LATEST SAFETY AND during Play mode. SHOULD...

  • Page 39: Sub Smps (Power) Schematic Diagram

    SCHEMATIC FOR EASY IDENTIFICATION. THIS CIRCUMSTANCES SHOULD THE ORIGINAL DESIGN CIRCUIT DIAGRAM MAY OCCASIONALLY DIFFER BE MODIFIED OR ALTERED WITHOUT PERMISSION FROM THE ACTUAL CIRCUIT USED. THIS WAY, FROM THE LG CORPORATION. ALL COMPONENTS IMPLEMENTATION OF THE LATEST SAFETY AND SHOULD REPLACED ONLY...

  • Page 40: Audio Main Schematic Diagram

    3. AUDIO MAIN SCHEMATIC DIAGRAM 3-26 3-27...

  • Page 41: Deck Schematic Diagram

    4. DECK SCHEMATIC DIAGRAM 3-28 3-29...

  • Page 42: Usb, Aux2 & Headphone Amp Schematic Diagram

    5. USB, AUX2 & HEADPHONE AMP SCHEMATIC DIAGRAM 3-30 3-31...

  • Page 43: I/O Jack Schematic Diagram

    6. I/O JACK SCHEMATIC DIAGRAM 3-32 3-33...

  • Page 44: Amp Schematic Diagram

    7. AMP SCHEMATIC DIAGRAM 3-34 3-35...

  • Page 45: Woofer Amp Schematic Diagram

    8. WOOFER AMP SCHEMATIC DIAGRAM 3-36 3-37...

  • Page 46: Front Schematic Diagram

    9. FRONT SCHEMATIC DIAGRAM 3-38 3-39...

  • Page 47: Printed Circuit Diagrams

    PRINTED CIRCUIT DIAGRAMS 1. MAIN P.C.BOARD (TOP VIEW) 3-40 3-41...
  • Page 48 MAIN P.C.BOARD (BOTTOM VIEW) 3-42 3-43...

  • Page 49: Smps (Power) P.c.board

    2. SMPS (POWER) P.C.BOARD 3. SUB SMPS (POWER) P.C.BOARD 3-44 3-45...
  • Page 50 4. FRONT P.C.BOARD (TOP VIEW) 3-46 3-47...

  • Page 51: Front P.c.board

    FRONT P.C.BOARD (BOTTOM VIEW) 3-48 3-49...

  • Page 52: Amp P.c.board

    5. AMP P.C.BOARD (TOP VIEW) (BOTTOM VIEW) 3-50 3-51...

  • Page 53: Woofer Amp P.c.board

    MEMO 6. WOOFER AMP P.C.BOARD 3-52 3-53...

  • Page 54: Dvd Part Electrical

    SECTION 4 DVD PART ELECTRICAL ELECTRICAL TROUBLESHOOTING GUIDE 1. POWER MICOM POWER ON (IC302) CHANGE PUSH KARAOKE DOES DOES DVD BUTTON AUX, FM 87.5 APPEAR DVD / CD APPER AT FLD? AT FLD? DOES DOES DISK1 APPEAR IT APPEAR DVD ERROR AT FLD? AT FLD? DOES NO...

  • Page 55: Test & Debug

    2. TEST & DEBUG POWER ON CHECK CONNECTION LINES FLASH BETWEEN FLASH & ES8381 OR SHOW LOGO? MEMORY OPERATES THE FLASH ACCESS TIME PROPERLY? WHETHER IS SUITABLE OR NOT. CHECK CONNECTION LINES BETWEEN SDRAM (IC502) & SDRAM WORKS ES8381 OR THE SDRAM IS PROPERLY? DAMAGED.
  • Page 56 DOES THE SLED LIMIT SW SIGNAL MOVE TO INNER SIDE CHECK THE MD ON P4407 IS LOW? WHEN IT IS AT OUTER POSITION? CHECK THE RELATED SLED CIRCUIT OF SLED AND SIGNAL IS OK? MOTOR DRIVER IC (IC401) CHECK THE CABLE CONNECTION WITH MECHA.
  • Page 57 CHECK THE LASER POWER DVDLD LASER CIRCUIT BETWEEN ES8381 OR CDLD OUTPUT TURNS ON WHEN AND POWER TRANSISTOR. PROPERLY? READING DISC? (Q405, Q406) COLLECTOR CHECK THE RELATED VOLTAGE OF POWER CIRCUIT OF LASER TRANSISTOR IS OK? POWER TRANSISTOR. (Q405, Q406) CHECK CABLE CONNECTION BETWEEN PDM01 AND PICK-UP HEAD.
  • Page 58 CHECK THE CONNECTIONS PROPER BETWEEN PDM01 AND SIGNAL ON A, B, C, FOCUS ON OK? PICK-UP HEAD. D FROM MD? CHECK THE RELATED PROPER CIRCUIT OF ES8381 FOO SIGNAL ON FOCUS SIGNAL. IC401? CHECK CABLE CONNECTION BETWEEN PDM01 AND MD. CHECK THE RELATED PROPER CIRCUIT BETWEEN IC401...
  • Page 59 CHECK THE CONNECTIONS AUDIO OUTPUTS ARE OK BETWEEN ES8381 AND SIGNAL DATA ON DURING PLAYING IC407, CN709 CN709 IS OK? DISK? CHECK THE MAIN PCB FOR EXAMPLE COMPOSITE VIDEO, CHECK THE VIDEO PICTURE MUTE TR (Q411), OUTPUT OF SIGNAL DATA ON VIDEO BUFFER IC (IC407) AND ES8381 IS OK? ES8381 VIDEO SIGNAL DATA...

  • Page 60: Usb

    3. USB TURN ON USB “SEARCHING” OR CHECK THE POWER SUPPLY CIRCUIT. “USB” DISPLAY CHECK (CHECK CN709) CHECK THE HRST# SIGNAL CHECK THE USB PART AND DVD PART LINE. CHECK THE USB JACK POWER SUPPLY. READING OK CHECK (CHECK P4302) CHECK THE USB DATA LINE.

  • Page 61: Waveforms

    WAVEFORMS 1. WHEN POWER ON, RESET & DATA ETC WAVEFORM 1. RESET(DVD) 2. RX 3. TX 4. LCS3# (FLASH) Playing at USB function 1. HRST# 2. 5V 3. D- 4. D+...

  • Page 62: Open / Close Waveform At Power On

    2. OPEN / CLOSE WAVEFORM AT POWER ON 1. open 2. UP-sw 3. DOWN-sw 4. close 3. STARTING ACTION WAVEFORM IN MD DEVICE 1. Driver STBY 2. SLEGN 3. SL+ 4. SL- (At Power on)

  • Page 63: Focus Waveform (At Cd)

    4. FOCUS WAVEFORM (AT CD) 1. F+ 2. F- (NO DISK) 5. FOCUS WAVEFORM (AT DVD) 1.Q401(DVD_LD) 2.Q402(CD_LD) (INSERT CD) 4-10...

  • Page 64: At Power On, Spindle Signal At Md Deck

    6. AT POWER ON, SPINDLE SIGNAL AT MD DECK 1. Spind 2. Spin+ 3. Spin- 7. AT FIRST ACTION, FOCUS SIGNAL A, B, C, D 1. A 2. B 3. C 4. D 4-11...

  • Page 65: Tracking Signal

    8. TRACKING SIGNAL 1. Tro 2. Tr- 3. Tr+ 9. RF WAVEFORM 4-12...

  • Page 66: Disk Type Jugement Waveform

    10. DISK TYPE JUGEMENT WAVEFORM (DVD) 1. F+ 2. FDO 3. SVRRF (CD) 4-13...
  • Page 67 MEMO 4-14...

  • Page 68: Schematic Diagrams

    SCHEMATIC DIAGRAMS 1. MPEG SCHEMATIC DIAGRAM 4-15 4-16...

  • Page 69: Servo Schematic Diagram

    2. SERVO SCHEMATIC DIAGRAM 4-17 4-18...

  • Page 70: Usb Schematic Diagram

    3. USB SCHEMATIC DIAGRAM 4-19 4-20...

  • Page 71: Interface Schematic Diagram

    4. INTERFACE SCHEMATIC DIAGRAM 4-21 4-22...

  • Page 72: Printed Circuit Diagram

    PRINTED CIRCUIT DIAGRAM DVD P.C.BOARD (TOP VIEW) 4-23 4-24...
  • Page 73 DVD P.C.BOARD (BOTTOM VIEW) 4-25 4-26...

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