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LG CD-372A Service Manual

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SECTION 1. SUMMARY
• SERVICING PRECAUTIONS ......................................................................................................... 1-2
• ESD PRECAUTIONS ...................................................................................................................... 1-4
• SPECIFICATIONS .......................................................................................................................... 1-5
SECTION 2. ELECTRICAL SECTION
• ADJUSTMENT ................................................................................................................................ 2-1
• TROUBLESHOOTING GUDIE ....................................................................................................... 2-2
• INTERNAL BLOCK DIAGRAM OF IC's ........................................................................................ 2-11
• IC VOLTAGE SHEET .................................................................................................................. 2-16
• BLOCK DIAGRAM ........................................................................................................................ 2-20
• SCHEMATIC DIAGRAMS ............................................................................................................. 2-22
• WIRING DIAGRAMS .................................................................................................................... 2-36
• PRINTED CIRCUIT BOARD DIARGAMS ..................................................................................... 2-38
SECTION 3. EXPLODED VIEWS
SECTION 4. REPLACEMENT PARTS LIST
[CONTENTS]
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- 1-1 -
3-1
4-1

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  Summary of Contents for LG CD-372A

  • Page 1 [CONTENTS] SECTION 1. SUMMARY ❍ • SERVICING PRECAUTIONS ......................1-2 • ESD PRECAUTIONS ........................1-4 • SPECIFICATIONS .......................... 1-5 ❍ SECTION 2. ELECTRICAL SECTION • ADJUSTMENT ..........................2-1 • TROUBLESHOOTING GUDIE ....................... 2-2 • INTERNAL BLOCK DIAGRAM OF IC’s ..................2-11 •...
  • Page 2: Section 1. Summary

    SECTION 1. SUMMARY ❏ SERVICING PRECAUTIONS [NOTES REGARDING HANDLING OF THE PICK-UP] – 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 —...
  • Page 3 [NOTES REGARDING COMPACT DISC PLAYER REPAIRS] – 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 4: 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 5: Specifications

    ❏ SPECIFICATIONS * Designs and specifications are subject to change without notice for improvement. - 1-5 -...
  • Page 6: Section 2. Electrical Section

    SECTION 2. ELECTRICAL SECTION ❏ ADJUSTMENT 1.AM ADJUSTMENT STEP ITEM SSG OUTPUT SET FREQUENCY ADJUSTMENT ADJUST FOR 450KHz 522(530)KHz T102 Maximum 1611(1610)kHz T101 5.5V SENSITIVITY 603(600)kHz 603(600)kHz L103 Maximum SENSITIVITY 1404(1400)kHz 1404(1400)kHz TC101 Maximum Repeat steps 3 and 4 for several times 2.FM ADJUSTMENT STEP ITEM...
  • Page 7: Troubleshooting Guide

    ❏ TROUBLESHOOTING GUIDE 1] CD PART • CD CIRCUIT CD PART Is the function selector in the CD position? Is power turned ON? Check power supply circuitry. Check laser circuitry. Does initial Reading occur? Check focusing circuitry. Check disc. Check tracking servo circuitry. Can disc be played? Is audio output supplied? Check Audio circuitry.
  • Page 8 (1) If display LCD lighting is abnormal Is the function selector in the CD position? (WITHOUT DISC) • Power supply circuitry Check voltage in the power Do display LCD then light? defective supply circuitry. • Check Q516 and CN603 • Reset circuit defective. Is µ-COM reset circuit •...
  • Page 9 (2) If initial reading is not carried out(with Disc) Is IC201 Pin42 output Dose disc motor rotate? waveform normal? • Limit SW contact defective. • Connector depective. • Patter short. Door open Door close Dose laser light? Is HF wave- •...
  • Page 10 When laser does not light Does lenses move up and down? Has Pick-up returned to the Are data transterred from • IC701 defective. innermost position? IC 701? • IC 601, 603 defective. Is below signal output at IC603 Pin17,18 ? •...
  • Page 11 When laser light Does lenses move up and down? Is signal output at focus • IC701 defective. search terminal? Is signal output at IC601 • IC 603 defective. 1, 2? • Actuator short. • Connector OPEN. Is IC601 pin2 signal waveform •...
  • Page 12 Is FSL signal Output? IC601 pin13 • IC701 defective. • Pick-up defective. • Connector defective. Is FEO signal output at IC601 When Fok focus Pin31 ? • IC 601 defective. Servo Conform by FEO signal. Is SMDS signal output • Pattern defective between by IC602 Pin13 ? •...
  • Page 13: Lcd Circuit

    2] LCD PART • LCD CIRCUIT If display LCD lighting is abnormal Is the function selector In the TUNER position? Is u-com reset circuit normal? Is u-com IC701 #17 pin and #18 (OSC) input? IC 701 #51,52,53 output Wave Form Normal? - 2-8 -...
  • Page 14: Main Circuit

    3] MAIN PART • MAIN CIRCUIT A. MAIN No Power at IC351 Pin 4,8 Is B+ applied Check Q501,502 and Q503 to PN501? Check Fuse(F501, F502) Is there a DC voltage Replace D501~D504 at the (+)terminal of D501~D504 Replace PN 501 B.
  • Page 15 C. CASSETT DECK DECK ABNORMAL. Is B+ applied to Q504? Is DECK LEAF SW normal? Check PN402. Replace LEAF SW. Is there a DC voltage at Check SW402. the Collector terminal of Q504 Replace Q504 D. TAPE REC TAPE REC ABNOMAL. Is oscillation Check S401 and Q402.
  • Page 16: Internal Block Diagram Of Ics

    ❏ INTERNAL BLOCK DIAGRAM OF ICs I LC72131 • Block Diagram • Pin Assignments (Top View) - 2-11 -...
  • Page 17 I TDA7440D • Block Diagram • Pin Assignments (Top View) - 2-12 -...
  • Page 18 I S3C8248 • Block Diagram • Pin Assignments (Top View) - 2-13 -...
  • Page 19 I TA2149BN • Block Diagram I KIA8207K(TA8207K) • Block Diagram - 2-14 -...
  • Page 20 I TDA2104(MP3 DECODER) • Block Diagram • Pin Assignments (Top View) - 2-15 -...
  • Page 21 ❏ IC/VR VOLTAGE SHEET IC101(TUNER MODE) Unit : V IC102(TUNER MODE) Unit : V IC401(TAPE MODE) Unit : V IC301(OUTPUT AMP) Unit : V IC351(OUTPUT AMP) Unit : V 15.6 17.5 15.7 IC601(CD MODE) Unit : V IC602(CD MODE) Unit : V IC603(CD MODE) Unit : V 2-16 2-17...
  • Page 22 IC701(ALL MODE) Unit : V Q516(CD MODE) Q515(CD MODE) Q518(TUNER MODE) Q517(TUNER MODE) Q102(TUNER MODE) Q103(TUNER MODE) Q101(TUNER MODE) Q401(TAPE MODE) Q402(TAPE MODE) Q505(TAPE MODE) Q504(TAPE MODE) Q503(ALL MODE) Q502(ALL MODE) Q501(ALL MODE) 15.5 16.1 16.1 16.6 16.5 15.7 17.2 16.5 16.5 Q351(ALL MODE)
  • Page 23: Block Diagram

    ❏ BLOCK DIAGRAM 2-20 2-21...
  • Page 24: Schematic Diagrams

    ❏ SCHEMATIC DIAGRAMS 1. MAIN SCHEMATIC DIAGRAM 2-22 2-23...
  • Page 25 2. µ-COM SCHEMATIC DIAGRAM 2-24 2-25...
  • Page 26 2. µ-COM SCHEMATIC DIAGRAM (FOR MP3) 2-26 2-27...
  • Page 27 3. TUNER SCHEMATIC DIAGRAM 2-28 2-29...
  • Page 28 4. CD SCHEMATIC DIAGRAM 2-30 2-31...
  • Page 29 4. CD SCHEMATIC DIAGRAM (FOR MP3) 2-32 2-33...
  • Page 30 5. DECODER SCHEMATIC DIAGRAM (FOR MP3) 2-34 2-35...
  • Page 31: Wiring Diagram

    ❏ WIRING DIAGRAM 2-36 2-37...
  • Page 32: Printed Circuit Board Diagrams

    ❏ PRINTED CIRCUIT BOARD DIAGRAMS 1. MAIN P.C. BOARD DIAGRAM (COMPONENT SIDE) 2-38 2-39...
  • Page 33 1. MAIN P.C. BOARD DIAGRAM (SOLDER SIDE) 2-40 2-41...
  • Page 34 2. µ-COM P.C. BOARD DIAGRAM (COMPONENT SIDE) 2. µ-COM P.C. BOARD DIAGRAM (COMPONENT SIDE) (FOR MP3) 2. µ-COM P.C. BOARD DIAGRAM (SOLDER SIDE SIDE) 2. µ-COM P.C. BOARD DIAGRAM (SOLDER SIDE SIDE) (FOR MP3) 2-42 2-43...
  • Page 35 3. CD P.C. BOARD DIAGRAM (COMPONENT SIDE) 3. CD P.C. BOARD DIAGRAM (SOLDER SIDE SIDE) 2-44 2-45...
  • Page 36: Section 3. Exploded Views

    SECTION 3. EXPLODED VIEWS NOTE) Refer to “SECTION 4 REPLACEMENT PARTS LIST” in order to look for the part number of each part. CAUTION Exposed blade will cause severe injury...
  • Page 37 MEMO MEMO...