LG LX-U250A Service Manual
  1. Manuals
  2. Brands
  3. LG Manuals
  4. Stereo System
  5. LX-U250A
  6. Service manual
LG LX-U250A Service Manual

LG LX-U250A Service Manual

Micro component system
Hide thumbs
Table of Contents

Advertisement

Quick Links

MICRO COMPONENT
SYSTEM
SERVICE MANUAL
MODEL: LX-U250A, LXS-U250
P/N : 3829RAP005X
NOVEMBER, 2005

Advertisement

Table of Contents
loading

Related Manuals for LG LX-U250A

Summary of Contents for LG LX-U250A

  • Page 1 MICRO COMPONENT SYSTEM SERVICE MANUAL MODEL: LX-U250A, LXS-U250 P/N : 3829RAP005X NOVEMBER, 2005...
  • Page 2 [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. Storage in conductive bag Drop 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: Specifications

    ❏ SPECIFICATIONS NOTE : Specification are subject to change without notice in the course of product improvement. - 1-5 -...
  • Page 7 - 1-6 -...

  • Page 8: Section 2. Electrical

    SECTION 2. ELECTRICAL ❏ TROUBLESHOOTING GUIDE CD PART TURN ON CD OPEN CLOSE CHECK CONNECTOR CHECK ( PN804, PN806 ) CHECK POWER SUPPLY CIRCUIT( PN806 ) CHECK MICOM INTERFACE CIRCUIT( PN805 ) “ READING ” DISPLAY CHECK CONNECTOR CHECK ( PN802, PN804, PN806 ) CHECK MICOM INTERFACE CIRCUIT( PN805 ) READING OK CHECK CONNECTOR CHECK(PN801,PN802)

  • Page 9: Open Close Ng

    OPEN CLOSE NG CONNECTOR LOCKING CHECK ( PN804 ) CHECK POWER SUPPLY CIRCUIT( PN805, PN806) DEFECTIVE MAIN PN 806 PIN 4 = 12V, PIN 5 = 6.2V POEWR SUPPLY PN805 PIN 1 = 5V DEFECTIVE MICOM CHECK VOLTAGE CHANGE OF OPEN CLOSE , AND IC802 INPUT VOLTAGE PIN 7, 8, 20 (=6.2V) (PN805 PIN 2:BTL_MUTE, 14:OPEN 15:CLOSE) DEFECTIVE...
  • Page 10 “ READING ” DISPLAY CHECK (= ONLY “CD “DISPLAY) CONNECTOR LOCKING CHECK (PN802, PN804,PN805,PN806 ) CHECK POWER SUPPLY DEFECTIVE CONNECTOR OR PORT( PN805 ,PN806) MAIN POWER SUPPLAY PN 806 PIN 4 = 12V, PIN 5 = 6.2V PN805 PIN 12 = 5V CHECK VOLTAGE THE PIN 2 OF IC804 DEFECTIVE IC804 IC804 PIN 2 : 3.3V...
  • Page 11 READING OK CHECK (= “NO DISC” DISPLAY) CONNECTOR LOCKING CHECK(PN801,PN802) DOES SLED MOVE ? DEFECTIVE PICKUP OR CHECK PN802 PIN 3,4( SL+,SL-) IC802 OR IC801 DOES LENSE MOVE ? (= UP & DOWN) DEFECTIVE PICKUP OR CHECK PN801 PIN 13,16( FA-, FA+) IC802 OR IC801 DOES LASER LIGHT ? CHECK PN801 PIN 10( LD )
  • Page 12 READING OK CHECK #A (= “NO DISC” DISPLAY) DOES SL+ WAVEFORM APPEAR ( 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 CHECK PN802 CONNECTOR LINE...
  • Page 13 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 FAIN- WAVEFORM APPEAR AT DEFECTIVE IC801 ( IC802 PIN 25) WAVEFORM #3 FOCUS DRIVE WAVE DEFECTIVE IC802 DEFECTIVE PN801...
  • Page 14 READING OK CHECK #C (= “NO DISC” DISPLAY) IS ?V APPLIED TO PIN10 OF PN501 LASER SUPPLY VOLTAGE CHECK IS 3.3 V APPLIED TO PIN30,36,39,41,61,68,75 OF IC801 DEFECTIVE IC804 RF IC SUPPLY VOLTAGE CHECK IS 2.3 V PIN18 OF IC801 DEFECTIVE IC801 LASER CONTROL VOLTAGE CHECK...
  • Page 15 READING OK CHECK #D (= “NO DISC” DISPLAY) DOES SP+ WAVEFORM APPEAR ( IC802 PIN 11 AND PN802 PIN 5) 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 16 READING OK CHECK #E (= “NO DISC” DISPLAY) DOES TA+ WAVEFORM APPEAR AT ( IC802 PIN 17 AND PN801 PIN 14) 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...

  • Page 17: Micom Interface Waveform

    ❏ WAVEFORMS OF MAKOR 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 3 : WRQ PIN 3 : WRQ PIN 4 : RESET PIN 4 : RESET PIN 5 : DO...

  • Page 18: Sled Drive And Motor Waveform

    #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 19: Spindle Drive And Motor Waveform

    #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 20 USB PART TURN ON USB “CHECKING ”OR “USB” DISPLAY CHECK CONNECTOR CHECK ( PN805, PN806, PN810 ) CHECK POWER SUPPLY CIRCUIT( PN806 ) CHECK MICOM INTERFACE CIRCUIT( PN805 ) READING OK CHECK CHECK PN810 1 PIN : 5V CHECK PN810 PIN 2(D-), 3(D+) CHECK OTI6888 (IC805) IF PLAY, AUDIO OUTPUT CHECK...

  • Page 21: Vkk Check

    P-SENS CHECK ZD900 (+)VOLTAGE CHECK (5V) D912(+)WAVE CHECK D912 CHANGE IC301 26PIN PATTERN CHECK VKK CHECK PN301 3Pin DC -27V CHECK ZD901 (-)-27V CHECK C921(-)-27V UNDER VOLT CHECK Q900 TURN ON CHECK Q900 CHANGE D907,D906 CHANGE VOLTAGE CHECK LIST - 2-14 -...

  • Page 22: Voltage Check

    VOLTAGE CHECK ALL Fuse CHECK FUSE CHANGE C904(+),C905(-)DC VOLT OUTPUT CHECK CN900 (-)1,2 PIN,(+)5,6 PIN OUTPUT VOLTAGE,D900 CHECK IC901,IC902 INPUT DC VOLT CHECK TransformerCHANGE D700 CHANGE CN901 7 Pin DC VOLTOUTPUT CHECK IC903 Output DC VOLT CHECK (6.2V) Transformer CHANGE D901,D902,D903,D904 COMPONENT CHECK AND CHANGE D909,D910 VOLT CHECK IC903 Output DC VOLT CHECK (6.2V)
  • Page 23 NO SOUND IC905 17,22 PIN OUTPUT CHECK IC905 Troubleshooting VIEW IC905 INPUT CHECK(FUNK BLOCK INPUT CHECK) Muting troubleshooting VIEW POWER CIRCUIT CHECK RY700 CONTROL CHECK SPK Relay troubleshooting VIEW SPK Relay Troubleshooting (ONLY LX-W550`s) D503 (+)12V CHECK VOLTAGE CHECK LIST Q511 Collector "Low"CHECK Q511 Base "High"...
  • Page 24 FUNCTION MODE (NO SOUND) TAPE IC905 3,36PIN INPUT SIGNAL CHECK IC204 Troubleshooting IC905 5,34 PIN INPUT SIGNAL CHECK JK600 INPUT CHECK IC905 4,35 PIN INPUT SIGNAL CHECK CD Troubleshooting TUNER IC905 2,37 PIN INPUT SIGNAL CHECK IC102 Troubleshooting DAB/L BAND/DAB+L IC905 6,33 PIN INPUT SIGNAL CHECK IC102 Troubleshooting - 2-17 -...
  • Page 25 IC301 Troubleshooting IC301 17,46,72,90 INUT VOLT.CHECK VOLTAGE CHECK LIST IC301 26Pin 5V INPUT CHECK P-SENS SECTION CHECK X301 CHECK X301 CHANGE IC301 17Pin VOLT INPUT (Low ➝ High) RESET SECTION CHECK IC301 CHANGE IC204 Troubleshooting IC204 16Pin INUT VOLT.CHECK VOLTAGE CHECK LIST IC204 2,3 Pin CLK Data CHECK IC301 3,4Pin Data CHECK (CD,TAPE FUNCTION MODE) IC301 TROUBLE SHOOTING...
  • Page 26 IC905 Troubleshooting FUNC CLOCK DATA 19,20PIN CHECK 21 PIN VOLT CHECK VOLTAGE CHECK LIST EACH FUNC MODE (INPUT SIGNAL CHECK) FUNC Troubleshooting EACH FUNC MODE (INPUT SIGNAL CHECK) SPK Relay SECTION CHECK 17,22 Pin OUTPUT SIGNAL CHECK FM(TUN600)CHECK TUN600 2PIN 9V CHECK VOLTAGE CHECK LIST TUN600 7,8,9PIN CLOCK DATA CHECK IC301 7,8,9 PIN CLOCK DATA CHECK...
  • Page 27 PLAY MODE CHECK IC201 46Pin VCC CHECK VOLTAGE CHECK LIST IC201 3,6 Pin Signal Output CHECK Deck Mecha MOVE CHECK Deck Mecha CHANGE Muting SECTION CHECK IC201 CHANGE REC CHECK (Q202,Q252 ON:R220,270 HIGH) IC203 2,8Pin INPUT SIGNAL CHECK Q202,Q252 Base "Low"CHECK IC203 Troubleshooting IC203 3,7 Pin OUT Q202,Q252 CHANGE...
  • Page 28 DAB/DAB+L /L BAND(DAB600,DAB600L)CHECK (ONLY DAB series MODEL) DAB600,DAB600L 4PIN 3.3V INPUT CHECK VOLTAGE CHECK LIST DAB600,DAB600L 11,13PIN PIN CLOCK DATA CHECK IC301 75,76 PIN CLOCK DATA CHECK DAB600,DAB600L 6,8PIN OUTPUT CHECK IC301 Troubleshooting DAB600,DAB600L CHANGE - 2-21 -...

  • Page 29: Internal Block Diagram Of Ics

    ❏ INTERNAL BLOCK DIAGRAM of ICs • NJW1190 BLOCK DIAGRAM - 2-22 -...
  • Page 30 PIN FUNCTION (SSOP44) - 2-23 -...
  • Page 31 PIN FUNCTION (QFP48-P1) - 2-24 -...
  • Page 32 • IC805 BLOCK DIAGRAM 14.318MHz Clock Divider RISC Input device Transceirver Button Interrupt Program decoder Bit Stream LED1~2 • PIN CONFIGUARTION GPIOA [7 ] GPIOB [2 ] GPIOA [6 ] GPIOB [0 ] xtal2 LED1_out xtal1 GPIOA [5 ] reset_b GPIOA [4 ] - 2-25 -...
  • Page 33 PIN CONFIGUARTION ex_romaddr [0 ] ex_romdata [5 ] ex_romaddr [1 ] ex_romdata [6 ] GPIOA [7 ] GPIOA [6 ] xtal2 LED1_out xtal1 GPIOA [5 ] GPIOA [4 ] reset_b ex_romaddr [12 ] mode0 ex_romaddr [11 ] ex_romdata [0 ] ex_romaddr [10 ] ex_romdata [1 ] ex_romaddr [9 ]...

  • Page 34: Pin Configuration

    • AM5810 (IC802) BLOCK DIAGRAM PIN CONFIGURATION BIAS OPIN4 ( + ) LDCONT OPIN4 ( - ) OP OUT4 INÅå OPIN3 ( + ) OPIN3 ( - ) PR EVCC OPOUT3 MUTE POWVCC12 VOL ( - ) POWVCC34 VOL ( + ) VO2 ( - ) VO3 ( - ) VO2 ( + )

  • Page 35: Pin Description

    PIN DESCRIPTION - 2-28 -...

  • Page 36: Block Diagram

    ❏ BLOCK DIAGRAM 2-29 2-30...
  • Page 37 • WMA/USB BLOCK DIAGRAM 2-31 2-32...

  • Page 38: Main Schematic Diagram

    ❏ SCHEMATIC DIAGRAMS • MAIN SCHEMATIC DIAGRAM 2-33 2-34...

  • Page 39: Front Schematic Diagram

    • FRONT SCHEMATIC DIAGRAM 2-35 2-36...

  • Page 40: Power Schematic Diagram

    • POWER SCHEMATIC DIAGRAM 2-37 2-38...

  • Page 41: Deck Schematic Diagram

    • DECK SCHEMATIC DIAGRAM 2-39 2-40...

  • Page 42: Cd Schematic Diagram

    • CD SCHEMATIC DIAGRAM 2-41 2-42...

  • Page 43: Usb Schematic Diagram

    • USB SCHEMATIC DIAGRAM 2-43 2-44...

  • Page 44: Wiring Diagram

    ❏ WIRING DIAGRAM 2-45 2-46...

  • Page 45: Printed Circuit Diagrams

    ❏ PRINTED CIRCUIT DIAGRAMS • MAIN P.C. BOARD 2-47 2-48...

  • Page 46: Front P.c. Board

    • FRONT P.C. BOARD 2-49 2-50...
  • Page 47 • CDP P.C. BOARD (COMPONENT SIDE) 2-51 2-52...
  • Page 48 • CDP P.C. BOARD (SOLDER SIDE) 2-53 2-54...
  • Page 49 • LINEAR POWER 2-55 2-56...

  • Page 50: Section 3. Exploded Views

    SECTION 3. EXPLODED VIEWS ❏ CABINET AND MAIN FRAME SECTION...
  • Page 51 • SINGLE DECK MECHANISM...
  • Page 52 • CD MECHANISM...

  • Page 54: Section 4. Speaker Section

    SECTION 4. SPEAKER SECTION ❏ MODEL: LXS-U250 - 4-1 -...
  • Page 55 - 4-2 -...

This manual is also suitable for:

Lxs-u250

Table of Contents