LG LX-U150X Service Manual
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LG LX-U150X Service Manual

LG LX-U150X Service Manual

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MICRO COMPONENT
SYSTEM
SERVICE MANUAL
MODEL : LX-U150X (LXS-U150)

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Summary of Contents for LG LX-U150X

  • Page 1 MICRO COMPONENT SYSTEM SERVICE MANUAL MODEL : LX-U150X (LXS-U150)

  • Page 2: Table Of Contents

    [CONTENTS] SECTION 1. GENERAL • SERVICING PRECAUTIONS ..........1-2 •...

  • Page 3: Section 1. General

    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 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 com- monly are called Electrostatically Sensitive Devices (ESD). Examples of typical ESD devices are integrated cir- cuits 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: Specification

    SPECIFICATIONS SECTION MODEL LX-U150A/D/X Power supply Refer to the back panel of the unit Power consumption General Mass External dimensions(WxHxD) 146x238x251mm Frequency Response 40 ~ 18000Hz Signal-to-noise ratio 60dB Dynamic Range 60dB Tuning Range 87.5 ~ 108.0MHz or 65 ~74MHz, 87.5 ~ 108.0MHz Intermediate Frequency 10.7MHz Signal-to-noise ratio...
  • Page 7 MEMO - 1-6 -...

  • Page 8: Section 2. Electrical

    SECTION 2. ELECTRICAL ADJUSTMENTS This set has been aligned at the factory and normally will not require further adjustment. As a result, it is not recommended that any attempt is made to modificate any circuit. If any parts are replaced or if anyone tampers with the adjustment, realignment may be necessary.

  • Page 9: Waveforms Of Major Check Point

    WAVEFORMS OF MAJOR CHECK POINT #1. MICOM INTERFACE WAVEFORM #1. MICOM INTERFACE WAVEFORM (PN805 PIN 3, 4, 5, 6) during power on (PN805 PIN 3, 4, 5, 6) during normal play PIN 14 : WRQ PIN 14 : WRQ PIN 4 : RESET PIN 4 : RESET PIN 6 : DO PIN 6 : DO...
  • Page 10 #2. SLED DRIVE AND MOTOR WAVEFORM #2. SLED DRIVE AND MOTOR WAVEFORM (IC802 PIN 5, 13) when focus search (IC802 PIN 5, 13) during normal play PIN 5 : SLIN PIN 5 : SLIN PIN 13 : SL+ PIN 13 : SL+ #3.
  • Page 11 #4. SPINDLE DRIVE AND MOTOR WAVEFORM #5. TRACK DRIVE AND MOTOR WAVEFORM (IC802 PIN 6, 11) when TOC reading (IC802 PIN 22 , IC802 PIN 17) during normal play PIN 22 : TAO PIN 6 : SPIN PIN 11 : SP+ PIN 17 : TA+ #6.

  • Page 12: Troubleshooting

    TROUBLESHOOTING • AUDIO PART P-SENS PART Does +5V appear at ZD902? D920 , CN901 Check IC300 PIN 26 Check POWER CIRCUIT Check the Fuse Replace the fuse Check the DC voltage of Check the DC output CN901 Pin3,4 Of C914(+) Replace the Transformer Replace the D908,909...
  • Page 13 MUTING CIRCUIT(MUTE) Does "High" appear at Q701, Q702 "B" Check the waveform Of D920(+) Replace ZD902 Check the "LOW" of Q701 Q901, "C" Replace the TR MUTE AUDIO ABNORMAL Check the Output of IC701 Pin 8,12 Check the speaker connection Check the Signal Output of IC701 pin2,4 Check the "High"...
  • Page 14 FUNCTION MODE AUDIO ABNORMAL TAPE Check the signal input of CN201, PN201 check IC601 pin3, 26 IC601 pin12, 17 output IC201 pin4, 11 check Check the signal input of Check signal input JK602 IC601 pin4, 25 IC601 pin12, 17 output Check the signal input of CN601 pin Check the signal input of 1, 3 and refer to CD troubleshooting...
  • Page 15 IC301 TROUBLESHOOTING Check the power supplying IC300 pin17,54,90 Refer to "Power Circuit Troubleshooting" Check the P-SENS "HIGH" of IC300 pin26 Check the P-SENS Check the oscillation of X301 Replace the X301 When power supplying to IC300 pin11. (Low High) Check the RESET circuit Replace the IC300 IC601 TROUBLESHOOTING Check the power supplying...
  • Page 16 IC103 TROUBLESHOOTING Check the Power input of IC103 Pin 17 D107 ,D108 ,IC902 Check X104 oscillation Replace X104 Check CE,DI,DO,CLK CE : Chip Enable DI : Data input (from Micom) DO : Data output (to Micom) Check the Operation CLK : Tuner mode clock AM COIL TROUBLESHOOTING Check the "High"...
  • Page 17 FM(TU101) TROUBLESHOOTING Check the 10V input of TU101 Pin 6 Check the 10V of Q102 "E" Check the Power circuit Check the "LOW" of IC103 Check the "High" of TU101 Pin5 pin7 Refer to "IC103 Troubleshooting" Replace the Q102 Check the OSC waveform of TU101 pin8 Refer the TU101 Refer to "IC102 Troubleshooting"...
  • Page 18 DECK PLAY Check the B+ Power to Leaf Switch Check PN201 , Q201 IC201 signal check Pin 4 , Pin 11 PN202 Check SW202 Check Audio output ( PN201 Pin 8 , Pin 9 ) RECORDING Check the signal output IC201 Pin 4 , Pin 11 Check the oscillation of L201 Check Leaf S/W B+...
  • Page 19 • CD PART TURN ON CD OPEN CLOSE CHECK CONNECTOR CHECK ( CN808 ,PN305 ) PN304 PIN 12 (LEAF S/W) VOLTAGE CHECK -. OPEN : 5V , CLOSE : 2.5V CHECK POWER SUPPLY CIRCUIT( PN601 ) CHECK MICOM INTERFACE CIRCUIT( PN305 ) "READING"...
  • Page 20 OPEN CLOSE NG CONNECTOR LOCKING CHECK ( CN808 ) CHECK POWER SUPPLY CIRCUIT( PN305,PN601) IC902(KIA7805) PN305 PIN 12 = 5V CHECK PN601 PIN 7 =5V DEFECTIVE MICOM PN305 PIN 13 (LEAF S/W) VOLTAGE CHECK OPEN : 5V , CLOSE : 2.5V IC300 PIN 20 (LEAF S/W) VOLTAGE CHECK DEFECTIVE IC300 - 2-13 -...
  • Page 21 "READING" DISPLAY CHECK (= ONLY "CD" DISPLAY) CONNECTOR LOCKING CHECK ( CN808,PN305,PN601 ) CHECK POWER SUPPLY PORT( PN305 ,PN601) DEFECTIVE CONNECTOR OR MAIN POWER SUPPLAY PN601 PIN 8 = 6.3V, PIN 7 = 5V CHECK VOLTAGE THE PIN 2 OF IC806 DEFECTIVE IC806 IC806 PIN2 : 3.3V CHECK RESET SIGNAL OF PN805...
  • Page 22 READING OK CHECK (= "NO DISC" DISPLAY) CONNECTOR LOCKING CHECK(PN801,PN802) DOES SLED MOVE ? CHECK PN802 DEFECTIVE PICKUP OR PIN 3,4( SL+,SL-) IC802 OR IC801 DOES LENSE MOVE ? (= UP & DOWN) DEFECTIVE PICKUP OR CHECK PN801 PIN 13,16 IC802 OR IC801 ( FA-,FA+) DOES LASER LIGHT ?
  • Page 23 READING OK CHECK #A (= "NO DISC" DISPLAY) DOES SL+ WAVEFORM APPEAR AT ( IC802 PIN 13 AND PN 802 PIN 3) WAVEFORM #2 SLED MOTOR WAVE DOES SLIN WAVEFORM APPEAR AT DEFECTIVE IC801 ( IC802 PIN 5) WAVEFORM #2 SLED DRIVE WAVE DEFECTIVE IC802 DEFECTIVE PN802...
  • Page 24 READING OK CHECK #B (= "NO DISC" DISPLAY) DOES FA+ WAVEFORM APPEAR AT ( IC802 PIN 16 AND PN801 PIN 13) WAVEFORM #3 FOCUS COIL DRIVE WAVE DOES FAO WAVEFORM APPEAR AT DEFECTIVE IC801 ( IC802 PIN 25) WAVEFORM #3 FOCUS DRIVE WAVE DEFECTIVE IC802 DEFECTIVE PN801...
  • Page 25 READING OK CHECK #C (= "NO DISC" DISPLAY) IS VOLTAGE APPLIED TO PIN10 OF PN501? LASER SUPPLY VOLTAGE CHECK IS 3.3 V APPLIED TO PIN30,36,39,41,61 OF IC801 DEFECTIVE IC804 RF IC SUPPLY VOLTAGE CHECK IS 2.3 V PIN18 OF IC801 DEFECTIVE IC801 LASER CONTROL VOLTAGE CHECK...
  • Page 26 READING OK CHECK #D (= "NO DISC" DISPLAY) DOES SP+ WAVEFORM APPEAR ( IC802 PIN 11 AND PN802 PIN 6) WAVEFORM #4 SPINDLE MOTOR DRIVE WAVE DOES SPIN WAVEFORM APPEAR AT DEFECTIVE IC801 ( IC802 PIN 6) WAVEFORM #4 SPINDLE DRIVE WAVE DEFECTIVE IC802 DEFECTIVE PN802 CHECK PN802 CONNECTOR LINE...
  • Page 27 READING OK CHECK #E (= "NO DISC" DISPLAY) DOES TA+ WAVEFORM APPEAR AT ( IC802 PIN 17 AND PN801 PIN 22) WAVEFORM #5 TRACKING COIL DRIVE WAVE DOES TAIN-WAVEFORM APPEAR AT DEFECTIVE IC801 ( IC802 PIN 22) WAVEFORM #5 TRACKING DRIVE WAVE DEFECTIVE IC802 DEFECTIVE PN802 CHECK PN802 CONNECTOR LINE...
  • Page 28 • USB PART TURN ON USB "CHECKING" OR "USB" DISPLAY CHECK CONNECTOR CHECK ( PN305, PN601, PN807 ) CHECK POWER SUPPLY CIRCUIT( PN806 ) CHECK MICOM INTERFACE CIRCUIT( PN805 ) READING OK CHECK CHECK PN807 1 PIN : 5V CHECK PN810 PIN 2(D-), 3(D+) CHECK OTI6888 (IC803) IF PLAY, AUDIO OUTPUT CHECK...
  • Page 29 MEMO - 2-22 -...

  • Page 30: Block Diagram

    BLOCK DIAGRAM - 2-23 - - 2-24 -...

  • Page 31: Schematic Diagrams

    SCHEMATIC DIAGRAMS • MAIN & DECK SCHEMATIC DIAGRAM - 2-25 - - 2-26 -...
  • Page 32 • CD & USB SCHEMATIC DIAGRAM - 2-27 - - 2-28 -...
  • Page 33 • FRONT, POWER & USB SCHEMATIC DIAGRAM - 2-29 - - 2-30 -...
  • Page 34 • TUNER SCHEMATIC DIAGRAM - 2-31 - - 2-32 -...

  • Page 35: Wiring Diagram

    WIRING DIAGRAM - 2-33 - - 2-34 -...

  • Page 36: Printed Circuit Diagrams

    PRINTED CIRCUIT DIAGRAMS • FRONT, POWER & USB P.C. BOARD (Top View) • FRONT, POWER & USB P.C. BOARD (Bottom View) - 2-35 - - 2-36 -...
  • Page 37 • MAIN/DECK P.C. BOARD (Top View) - 2-37 - - 2-38 -...
  • Page 38 • MAIN/DECK P.C. BOARD (Bottom View) - 2-39 - - 2-40 -...
  • Page 39 • CD P.C. BOARD(Top View) • CD P.C. BOARD(Bottom View) - 2-41 - - 2-42 -...

  • Page 40: Internal Block Diagram Of Ics

    INTERNAL BLOCK DIAGRAM OF ICs IC300 LC877B80A O_PBMUTE P06 V3/PL6 O_FUNCLK P07 PF7/S47 O_LOADRDOUT P10/SO0 [Download] DATA_O PF6/S46 S41 I_LOADRDIN P11/SI0/SB0 [Download] DATA_I PF5/S45 S40 O_LOADRCLK P12/SCK0 [Download] CLOCK PF4/S44 S39 O_USB_TX P13/SO1 PF3/S43 S38 I_USB_RX P14/SI1/SB1 PF2/S42 S37 I_RDSDATA P15/SCK1 PF1/S41 S36 O_AMUTE P16/T1PWML Pf0/S40 S35...
  • Page 41 IC601 TDA7468D 1) BLOCK DIAGRAM - 2-44 -...
  • Page 42 2) PIN COFIGURATION - 2-45 -...
  • Page 43 IC301 BU1923F 1) BLOCK DIAGRAM 2) PIN COFIGURATION - 2-46 -...
  • Page 44 IC102 LA1837 1) BLOCK DIAGRAM 2) TEST CIRCUIT DIAGRAM - 2-47 -...
  • Page 45 IC103 LC72131 - 2-48 -...
  • Page 46 IC201 AN7312 IC701 LA4631 - 2-49 -...
  • Page 47 IC503 SA5810 1) PIN COFIGURATION 2)BLOCK DIAGRAM IC801 LC78690W 1) PIN COFIGURATION 2)BLOCK DIAGRAM CLOCK DOUT PLL2 GENERATOR LRSY EFMIN EFMIN SLICE LEVEL LRSY DATACK RFOUT 1bit DAC AUDIO CONTROL RFOUT DATACK DATA 8FS DIGITAL FILTER DATA TEST1 PHLPF DEEMPHASIS PHLPF TEST1 STDATA...

  • Page 48: Section 3. Exploded Views

    SECTION 3. EXPLODED VIEWS CABINET AND MAIN FRAME SECTION NOTE) Refer to “SECTION 5 REPLACEMENT PARTS LIST” in order to look for the part number of each part. T901 - 3-1 - - 3-2 -...
  • Page 49 MEMO MEMO - 3-3 - - 3-4 -...

  • Page 50: Section 4. Speaker

    SECTION 4. SPEAKER SECTION MODEL: LXS-U150 - 4-1 -...
  • Page 51 MEMO - 4-2 -...

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