LG DM2740 Service Manual
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LG DM2740 Service Manual

Dvd micro hi-fi system
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Internal Use Only
Website http://biz.lgservice.com
DVD Micro Hi-Fi System
SERVICE MANUAL
MODEL: DM2740
(DM2740, CMS2730F)
CAUTION
BEFORE SERVICING THE UNIT, READ THE "SAFETY PRECAUTIONS"
IN THIS MANUAL.
P
N /
O
:
A
F
N
76615056
JUNE
,
2
0
1
4

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Summary of Contents for LG DM2740

  • Page 1 Internal Use Only Website http://biz.lgservice.com DVD Micro Hi-Fi System SERVICE MANUAL MODEL: DM2740 (DM2740, CMS2730F) CAUTION BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS” IN THIS MANUAL. 76615056 JUNE...
  • Page 2 CONTENTS SECTION 1 ..SUMMARY SECTION 2 ..CABINET & MAIN CHASSIS SECTION 3 ..ELECTRICAL SECTION 4 ..REPLACEMENT PARTS LIST...

  • Page 3: Table Of Contents

    SECTION 1 SUMMARY CONTENTS SERVICING PRECAUTIONS ........................1-3 ESD PRECAUTIONS ..........................1-5 FIRMWARE UPGRADE ..........................1-6 1. MPEG 2. AUDIO MICOM 3. TOUCH EEPROM OPTION SETTING ........................1-7 SYSTEM RESET ............................1-7 SPECIFICATIONS ............................1-8...

  • Page 4: Servicing Precautions

    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 5 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 6: 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 7: Firmware Upgrade

    FIRMWARE UPGRADE 1. MPEG 1) Copy fi rmware to USB (Do not change fi le name). Ex) LG_DM2740LD1_1403190.rom 2) Change function to DVD/CD by pressing input key, and wait until home menu is shown. 3) Inset USB device which includes fi rmware. 4) Firmware is detected automatically and then, shows blue screen in TV.

  • Page 8: Eeprom Option Setting

    EEPROM OPTION SETTING 1) Change function to DVD/CD by pressing input key, and wait until home menu is shown. - Do not insert disc or USB at the set. 2) Press "PAUSE 1 4 7 2" in order. 3) and then, option setting menu is displayed. You can see 10 bytes option value.

  • Page 9: Specifications

    SPECIFICATIONS • GENERAL Power requirements Refer to the main label. Power consumption Refer to the main label. Dimensions (W x H x D) (135 x 295 x 315) mm Net Weight (Approx.) 3.7 kg Operating temperature 41 °F to 95 °F (5 °C to 35 °C) Operating humidity 5 % to 90 % •...
  • Page 10 SECTION 2 CABINET & MAIN CHASSIS CONTENTS EXPLODED VIEWS ............................. 2-1 1. CABINET AND MAIN FRAME SECTION (DM2740) ................2-3 2. DECK MECHANISM SECTION (SDP-08) ....................2-5 3. PACKING ACCESSORY SECTION ......................2-7 4. SPEAKER SECTION (CMS2730F)......................2-8...

  • Page 12: Exploded Views

    EXPLODED VIEWS 1. CABINET AND MAIN FRAME SECTION (DM2740) NOTES) THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIANGLE IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN SERVICE LITERATURE. 260L SMPS MAIN CABLE2 260R FRONT...

  • Page 13: Deck Mechanism Section (Sdp-08)

    2. DECK MECHANISM SECTION (SDP-08) 023C 023B...

  • Page 14: Packing Accessory Section

    3. PACKING ACCESSORY SECTION 823 HDMI cable 801 Owner’s Manual 825 FM antenna 808 Battery 900 Remote control 811 Video cable 803 Packing 804 Bag 802 Box...

  • Page 15: Speaker Section (Cms2730F)

    4. SPEAKER SECTION (CMS2730F) A60R A60L...
  • Page 16 SECTION 3 ELECTRICAL CONTENTS ONE POINT REPAIR GUIDE ..........................3-2 1. NO POWER PROBLEM ......................... 3-2 2. SPEAKER NO AUDIO OUTPUT ......................3-3 3. USB NO DETECT ........................... 3-4 4. NO BOOTING ............................3-5 ELECTRICAL TROUBLESHOOTING GUIDE ....................3-6 1. POWER (SMPS) ............................. 3-6 2.

  • Page 17: One Point Repair Guide

    ONE POINT REPAIR GUIDE 1. NO POWER PROBLEM No power problem occurs when you power on the unit. 1-1. Solution Replace X100, IC101, IC103. 1-2. How to troubleshoot (Countermeasure) 1) Check X100 (Crystal). If it does not oscillate, change X100. 2) Check IC103 (Reset IC).

  • Page 18: Speaker No Audio Output

    ONE POINT REPAIR GUIDE 2. SPEAKER NO AUDIO OUTPUT No audio output problem occurs when you power on the unit. 2-1. Solution Reassemble AMP IC heat-sink, replace IC700. 2-2. How to troubleshoot (Countermeasure) 1) Reassemble AMP IC heat-sink (heat-sink screw must be assembled tightly). 2) Still NG, please check IC700 Pin1, 2, 22(12 V), Pin29, 30, 31, 36, 37, 38 (26 V).

  • Page 19: Usb No Detect

    ONE POINT REPAIR GUIDE 3. USB NO DETECT When USB insert, USB no detect on the unit. 3-1. Solution Replace IC311. 3-2. How to troubleshoot (Countermeasure) 1) Please check IC311. Pin3 : 5 V 2) If it is not OK, replace IC3A8. 3-3.

  • Page 20: Booting

    ONE POINT REPAIR GUIDE 4. NO BOOTING When you turn on unit, it will display “Hello” or “Please wait” message continuously on front panel, and it will not boot-up normally. 4-1. Solution Replace X500. 4-2. How to troubleshoot (Countermeasure) 1) Please check the soldering status of 27 MHz crystal (X500). 2) Please check the frequency of 27 MHz crystal (X500).

  • Page 21: Electrical Troubleshooting Guide

    ELECTRICAL TROUBLESHOOTING GUIDE 1. POWER (SMPS) Power (AC cord in) Check if PVDD voltage of CN901 on Main BD Detach harness of CN901. is 25~26 V. Check if PVDD voltage of CN901 on SMPS BD Replace SMPS BD. is 25~26 V. Replace IC907.

  • Page 22: Μ-Com Part Check-1

    ELECTRICAL TROUBLESHOOTING GUIDE 4. μ-COM PART CHECK-1 μ-com part check-1 Check Refer to L206 3.7VA. SMPS troubleshooting. Check Check If emitter voltage of Q103 both end voltage Check the periphery of Q103. is over 3.7 V. of R186. Check if Q103 of collector Check voltage of IC101 Pin4.

  • Page 23: Fld Display Check

    ELECTRICAL TROUBLESHOOTING GUIDE 6. FLD DISPLAY CHECK FLD display check Check Refer to IC205 Pin7(26 V) SMPS troubleshooting. voltage. Check if both end voltage of FL+, FL- are -24V, -28V VKK : -31V. Check IC301 Check CN301 connection. Pin9 (3.3 V) Pin50 VKK (-31 V).

  • Page 24: Touch Part Check

    ELECTRICAL TROUBLESHOOTING GUIDE 7. TOUCH PART CHECK Touch part check IC303 Pin1 Check the FFC cable. voltage 3.3 V OK? Check TOUCH_IRQ signal(IC303 Pin6) When you touch pad, it is ‘Low’. Replace IC303. When you non-touch pad, it’s ‘High’. Check the connection, TOUCH_DAT, or replace IC101.

  • Page 25: Pwm Modulation Check

    ELECTRICAL TROUBLESHOOTING GUIDE 8. PWM MODULATION CHECK PWM modulation part check Check IC203 DC/DC circuit IC602 Pin9, 14, 35, 50 and replace IC602. 3.3 V. Check X600 12.288 MHz Replace X600. operation. Check IC602 line resistor output Pin16: PWM RESET Replace related resistor.

  • Page 26: Power Amp Part Check

    ELECTRICAL TROUBLESHOOTING GUIDE 9. POWER AMP PART CHECK Power AMP part check CN901 Refer to SMPS troubleshooting. Pin1, 2, 3: 26 V. Check each IC700 Pin29, 30, 31, 36, 37, 38 voltage. Check Check each line resistor output voltage. IC700 Pin1, 2, 22: +12 V input.

  • Page 27: Video Part Check

    ELECTRICAL TROUBLESHOOTING GUIDE 10. VIDEO PART CHECK Video part check Check each Check or replace D502. pin of D502 are short with each other? Check or replace JK501 Pin3 L501, C567, C568, R599. video signal OK? Check external Replace the cable. cable OK? If it’s still NG, check display device(TV or monitor).

  • Page 28: Tuner Function Check

    ELECTRICAL TROUBLESHOOTING GUIDE 11. TUNER FUNCTION CHECK Tuner function check Check Check tuner module voltage tuner module(TU100) (Pin6 : +3.3 V). operation. Check IC201(CS5346) Pin41,42,43,44 Replace the module. output waveform. Check or replace IC201, IC207. Waveform OK? Check IC500 Pin48, 49, 50, 51 I2S signal. Replace IC500.

  • Page 29: Details And Waveforms On System Test And Debugging

    DETAILS AND WAVEFORMS ON SYSTEM TEST AND DEBUGGING 1. SYSTEM 27 MHz CLOCK,RESET,FLASH R/W SIGNAL 1) MT1389FE/GH main clock is at 27 MHz(X500) IC500 FIG 1-1 2) MT1389FE/GH reset is high active. 3.3 V 1.2 V DVD_RESET IC500 FIG 1-2 IC500 3-14...
  • Page 30 3) Flash R/W enable signal during download(Downloading) SF_DI SF_DO FIG 1-3 3-15...

  • Page 31: Sdram Clock

    2. SDRAM CLOCK 1) MT1389FE/GH main clock is at 27 MHz(X500) DCLK = 93MHz, Vp-p=2.2, Vmax=2.7V SDCLK IC502 FIG 2-1 3. VIDEO PART (100% FULL COLOR-BAR) CVBS 3-16...

  • Page 32: Hdmi Part

    4. HDMI PART HDMI_SDA HDMI_SCL HDMI_CLK HDMI_DATA 3-17...
  • Page 33 3-18...

  • Page 34: Wiring Diagram

    WIRING DIAGRAM MAIN (FR-4 EPOXY 2LAYER) SMPS Harness LOADER Harness CN100 CN107 CN102 Harness FRONT VFD FRONT JACK (FR-4 EPOXY (FR-4 EPOXY 2LAYER) 2LAYER) 3-19 3-20...

  • Page 35: Block Diagram

    BLOCK DIAGRAM PVDD(26V) 3.3V 3.3V 3.3/5V 3.3V 3.3V EEPROM 12 MHz (2KByte) TUNER L/R LC87F5NC8A TUNER(FM) SANYO I2C,RESET PORT L/R (100PIN) PORTABLE (CS5346) TAS5548 TAS5612L T T S A A 5612L DAB L/R 32.768kHz CTRL option 3.3V 3.3/1.2V TPA6132A2 MCK,LRCK MCLK,LRCK, BCK,DATA 3.3V 27 MHz...

  • Page 36: Circuit Diagrams

    FROM THE ACTUAL CIRCUIT USED. THIS WAY, 2. Voltages are DC-measured with a digital voltmeter 1. SMPS CIRCUIT DIAGRAM FROM THE LG CORPORATION. ALL COMPONENTS IMPLEMENTATION OF THE LATEST SAFETY AND during Play mode. SHOULD BE REPLACED ONLY WITH TYPES PERFORMANCE IMPROVEMENT CHANGES INTO IDENTICAL TO THOSE IN THE ORIGINAL CIRCUIT.

  • Page 37: Main - Micom Circuit Diagram

    2. MAIN - MICOM CIRCUIT DIAGRAM MICOM EAX65726401_6.1.2_MAIN_SD 2014. 03. 28 3-25 3-26...

  • Page 38: Main - Mpeg Circuit Diagram

    3. MAIN - MPEG CIRCUIT DIAGRAM MPEG : WAVEFORM NUMBER EAX65726401_6.1.2_MAIN_SD 2014. 03. 28 3-27 3-28...

  • Page 39: Main - Rf Servo Circuit Diagram

    4. MAIN - RF SERVO CIRCUIT DIAGRAM RF SERVO EAX65726401_6.1.2_MAIN_SD 2014. 03. 28 3-29 3-30...

  • Page 40: Main - I/O & Adc Circuit Diagram

    5. MAIN - I/O & ADC CIRCUIT DIAGRAM I/O & ADC EAX65726401_6.1.2_MAIN_SD 2014. 03. 28 3-31 3-32...

  • Page 41: Main - Pwm & Amp Circuit Diagram

    6. MAIN - PWM & AMP CIRCUIT DIAGRAM PWM & AMP EAX65726401_6.1.2_MAIN_SD 2014. 03. 28 3-33 3-34...

  • Page 42: Front Vfd Circuit Diagram

    7. FRONT VFD CIRCUIT DIAGRAM FRONT VFD EAX65726601_10.1.3_VFD_SD 2014. 03. 26 3-35 3-36...

  • Page 43: Front Jack Circuit Diagram

    8. FRONT JACK CIRCUIT DIAGRAM FRONT JACK EAX65726701_10.1.3_JACK_SD 2014. 03. 26 3-37 3-38...

  • Page 44: Circuit Voltage Chart

    CIRCUIT VOLTAGE CHART 1. ICs LOCATION NAME SPEC CLASSIFICATION PIN NUMBER SPEC ENG. VOLTAGE REAL VOLTAGE MAIN BOARD 3.3VA 14 PIN 3.30 3.42 IC101 IC,Microcontrollers LC87F5WC8A 2.2 ~ 5.5 3V3MICOM 40,55,89 PIN 3.30 3.48 IC102 IC,EEPROM M24C16 3V3MICOM 8PIN 1.8 ~ 3.6 3.30 3.48 IC103...

  • Page 45: Connectors

    2. CONNECTORS LOCATION PIN NUMBER SPEC REAL VOLTAGE LOCATION PIN NUMBER SPEC REAL VOLTAGE MAIN SMPS 1,2,3 PVDD 25.4 1,2,3 PVDD 25.4 CN202 CN901 4,5,6 DGND 4,5,6 DGND MAIN TOP JACK 4,9,10,12 DGND 4,9,10,12 CN107 CN370 (TOP JCAK) USB_5.6V VCC_5V MAIN 3,7,14 DGND...

  • Page 46: Printed Circuit Board Diagrams

    PRINTED CIRCUIT BOARD DIAGRAMS 1. SMPS P.C.BOARD (TOP VIEW) 3-43 3-44...
  • Page 47 SMPS P.C.BOARD NOTE) Warning (BOTTOM VIEW) Parts that are critical with respect to risk of fire or electrical shock. 3-45 3-46...

  • Page 48: Main P.c.board

    2. MAIN P.C.BOARD (TOP VIEW) (BOTTOM VIEW) 3-47 3-48...

  • Page 49: Front Vfd P.c.board

    3. FRONT VFD P.C.BOARD (TOP VIEW) (BOTTOM VIEW) 3-49 3-50...

  • Page 50: Front Jack P.c.board

    4. FRONT JACK P.C.BOARD (TOP VIEW) (BOTTOM VIEW) 3-51 3-52...
  • Page 51 3-53 3-54...

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Cms2730f

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