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LG CJ44 Service Manual
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LG CJ44 Service Manual

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Internal Use Only
Mini Hi-Fi System
SERVICE MANUAL
MODEL: CJ44
(CJ44, CJS45F)
CAUTION
BEFORE SERVICING THE UNIT, READ THE "SAFETY PRECAUTIONS"
IN THIS MANUAL.
P/NO : AFN77612119
JANUARY, 2017

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  • Page 1 Internal Use Only Mini Hi-Fi System SERVICE MANUAL MODEL: CJ44 (CJ44, CJS45F) CAUTION BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS” IN THIS MANUAL. P/NO : AFN77612119 JANUARY, 2017...
  • Page 2 CONTENTS SECTION 1 ..GENERAL 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 HIDDEN KEY MODE ............................1-6 1. HIDDEN KEY MODE TABLE ........................1-6 2. HIDDEN KEY MODE DESCRIPTION ....................... 1-7 SERVICE INFORMATION FOR EEPROM ......................1-9 PROGRAM DOWNLOAD GUIDE ........................1-10 FOTA UPDATE STEP USING BT APP ......................

  • 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: Hidden Key Mode

    HIDDEN KEY MODE 1. HIDDEN KEY MODE TABLE HIDDEN MODE ENTRANCE KEY(Audio) EXIT KEY Front ‘Stop’  Version Check Remote Control Key ‘Play’ for 1.5s + Remote Control Key ‘Play’ for 5s Front ‘Stop’  EEPROM INITIAL Auto exit + Remote Control Key ‘ ‘...

  • Page 8: Hidden Key Mode Description

    2. HIDDEN KEY MODE DESCRIPTION 2-1. Version Check - Function : Version Check. - Entrance Key : Front ‘Stop’ + Remote Control Key ‘Play’ for 5s. - Exit Key : Remote Control Key ‘Play’ for 1.5s. - Operation explanation : Remote Control Key VFD Display (Example) Result MCS Version...
  • Page 9 2-5. Disc Lock On/Off - Function : Lock Open Key. - Entrance Key : Front ‘Stop’ + Remote Control Key ‘Stop’ for 5s. - Exit Key : Front ‘Stop’ + Remote Control Key ‘Stop’ for 5s. - Operation Explain : Open Key Block ‘LOCKED’. 2-6.

  • Page 10: Service Information For Eeprom

    SERVICE INFORMATION FOR EEPROM POWER ON It is possible at any function. (ex. It is possible at VFD “NO USB” status, too.) VFD “NO DISC” status This is an example. Front ‘Stop’ + Remote control ‘ ’ DETECT NEW EEPROM push same timing during 5 s (OPTION EDIT SCREEN) NAME...

  • Page 11: Program Download Guide

    PROGRAM DOWNLOAD GUIDE 1. CD PROGRAM Download program file name must be HG740_CJ44_YYMMDDX.bin If security program(Water Wall) is activated on PC, you must save the file to the USB storage device and disable the security software, then download the file to your set. Downloading file proceeds in the same way at USB1 function and USB2 function.
  • Page 12 2. EQ & DEMO PROGRAM Download program file name must be EQ_PRG.BIN If security program(Water Wall) is activated on PC, you must save the file to the USB storage device and disable the security software, then download the file to your set. Downloading file proceeds in the same way at USB1 function and USB2 function.

  • Page 13: Fota Update Step Using Bt App

    FOTA UPDATE STEP USING BT APP Step1 : App connecting Step2 : Device version info (Check FW version) After connecting the BT App with SET, When touch the “Device Version info” button, the user could fi nd the “Device Version info” on user could fi...
  • Page 14 Step5 : Download from CDN server Step6 : Transfer FW 1st step is download from CDN server to After completed the download from server, smart phone. The progress bar is displayed smart phone start to transfer the fi rmware to the on BT App.

  • Page 15: Specifications

    SPECIFICATIONS • GENERAL Power requirements Refer to the main label on the unit. Power consumption Refer to the main label on the unit. Networked standby : 0.5 W (If all network ports are activated.) Dimensions (W x H x D) Approx.
  • Page 16 SECTION 2 CABINET & MAIN CHASSIS CONTENTS EXPLODED VIEWS ............................2-3 1. CABINET AND MAIN FRAME SECTION ....................2-3 2. PACKING ACCESSORY SECTION ......................2-7 3. SPEAKER SECTION ..........................2-8 DISASSEMBLY INSTRUCTIONS ........................2-9 1. Case Top ..............................2-9 2. Bracket ..............................2-9 3.

  • Page 18: Exploded Views

    EXPLODED VIEWS 1. CABINET AND MAIN FRAME SECTION 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. MAIN SMPS CABLE1 CABLE2 FRONT...

  • Page 20: Packing Accessory Section

    2. PACKING ACCESSORY SECTION Battries 801 Owner’s manual 900 Remote control FM antenna Packing 804 Bag 802 Box...

  • Page 21: Speaker Section

    3. SPEAKER SECTION • FRONT SPEAKER...

  • Page 22: Disassembly Instructions

    DISASSEMBLY INSTRUCTIONS 1. Case Top 1-1) Remove the 5 Screws. 1-2) Remove the Case Top. Figure 1 2. Bracket 2-1) Remove the two Brackets between Front & Back Panel. You can easily remove the Bracket after the hook detach from Front Panel. Figure 2...

  • Page 23: Panel Rear

    3. Panel Rear 3-1) Remove the 4 Screws from the Panel Rear. 3-2) Remove the Power Cord & FAN Cable from the SMPS Board. 3-3) Remove the Panel Rear. Figure 3 2-10...

  • Page 24: Main Board & Smps Board

    4. MAIN Board & SMPS Board 4-1) Remove the 9 Screws from the MAIN Board & SMPS Board. 4-2) Remove the 6 Cables from the MAIN Board. 4-3) Remove the Power Cord from the SMPS Board. 4-4) Remove the MAIN Board & SMPS Board. Figure 4 2-11...

  • Page 25: Main Pcb & Smps Pcb

    5. Main PCB & SMPS PCB 5-1) Remove the 2 Screws. 5-2) Unhook the 5 Locking Tabs by using Flat-head screwdriver. 5-3) Remove the Panel Front Assembly. Figure 5 2-12...

  • Page 26: Panel Pcb & Multi Knob

    6. Panel PCB & Multi Knob 6-1) Multi Knob 6-1-1) Insert a Flat-head screwdriver in the hole (H1). 6-1-2) Remove the Multi Knob. 6-2) Jack PCB 6-2-1) Remove the 2 Screws. 6-2-2) Remove the Jack PCB. 6-3) BT Module 6-3-1) Unhook the Locking tab (L1). 6-3-2) Remove the BT Module.

  • Page 27: Bracket Smps

    7. Bracket SMPS 7-1) Remove the Bracket SMPS. Figure 7 8. MD 8-1) Remove the 2 Screws from the MD. 8-2) Remove the MD. Figure 8 2-14...
  • Page 28 SECTION 3 ELECTRICAL CONTENTS ONE POINT REPAIR GUIDE ..........................3-2 1. NO POWER ............................3-2 2. NO BOOTING WHEN POWER ON THE SET..................3-4 3. VFD IS NOT DISPLAYED WHEN POWER ON THE SET ..............3-5 4. NO OPERATION OF MD ........................3-6 5. NO SOUND ............................3-11 ELECTRICAL TROUBLESHOOTING GUIDE ....................3-17 1.

  • Page 29: One Point Repair Guide

    ONE POINT REPAIR GUIDE 1. NO POWER If the unit doesn’t work by no power problem, repair the set according to the following guide. 1-1. FUSE & BRIDGE DIODE 1-1-1. Solution Please check and replace F901, BD901, TH901 or TH903 on SMPS board. 1-1-2.
  • Page 30 ONE POINT REPAIR GUIDE NO POWER If the unit doesn’t work by no power problem, repair the set according to the following guide. 1-2. D951 1-2-1. Solution Please check and replace D951 on SMPS board. 1-2-2. How to troubleshoot (Countermeasure) 1) Check the anode-cathod voltage of D951 with a digital multi-meter, it is normally 0.2 ~ 0.3 V.

  • Page 31: Booting When Power On The Set

    ONE POINT REPAIR GUIDE 2. NO BOOTING WHEN POWER ON THE SET The set doesn’t work when press the power button on the front board or the remote control. 2-1. FLASH MEMORY 2-1-1. Solution Please check and replace IC501 on MAIN board. 2-1-2.

  • Page 32: Vfd Is Not Displayed When Power On The Set

    ONE POINT REPAIR GUIDE 3. VFD IS NOT DISPLAYED WHEN POWER ON THE SET When power on the set, any icons or characters on VFD are not displayed. 3-1. VFD 3-1-1. Solution Please check and replace VFD300 on FRONT board. 3-1-2.
  • Page 33 ONE POINT REPAIR GUIDE 4. NO OPERATION OF MD When no sound output in the CD function, you can not listen to music reading data from a CD disc if the servo motors in MD don’t work. This step is for checking the SPINDLE MOTOR among them. 4-1.

  • Page 34: Operation Of Md

    ONE POINT REPAIR GUIDE NO OPERATION OF MD When no sound output in the CD function, you can not listen to music reading data from a CD disc if the servo motors in MD don’t work. This step is for checking the SLED MOTOR among them. 4-2.
  • Page 35 ONE POINT REPAIR GUIDE NO OPERATION OF MD When no sound output in the CD function, you can not listen to music reading data from a CD disc if the servo motors in MD don’t work. This step is for checking the TRAY OPEN / CLOSE MOTOR among them.
  • Page 36 ONE POINT REPAIR GUIDE NO OPERATION OF MD When no sound output in the CD function, you can not listen to music reading data from a CD disc if the pickup module in MD doesn’t work. This step is for checking the LASER TRACKING ACTUATOR. 4-4.
  • Page 37 ONE POINT REPAIR GUIDE NO OPERATION OF MD When no sound output in the CD function, you can not listen to music reading data from a CD disc if the pickup module in MD doesn’t work. This step is for checking the LASER FOCUSING ACTUATOR. 4-5.
  • Page 38 ONE POINT REPAIR GUIDE 5. NO SOUND There is no sound output in the CD FUNCTION, repair the set according to the following guide. 5-1. IN THE CD FUNCTION 5-1-1. Solution Please check and replace IC501, IC601 on MAIN board. 5-1-2.

  • Page 39: Sound

    ONE POINT REPAIR GUIDE NO SOUND There is no sound output by DIGITAL AUDIO AMP DAMAGE, repair the set according to the following guide. 5-2. BY DIGITAL AUDIO AMP DAMAGE (IN ALL FUNCTIONS) 5-2-1. Solution Please check and replace IC701, IC702 on MAIN board. 5-2-2.
  • Page 40 ONE POINT REPAIR GUIDE NO SOUND There is no sound output in the USB FUNCTION, repair the set according to the following guide. 5-3. IN THE USB FUNCTION 5-3-1. Solution Please check and replace IC500 on MAIN board & IC104 on USB board. 5-3-2.
  • Page 41 ONE POINT REPAIR GUIDE NO SOUND There is no sound output in the AUX FUNCTION, repair the set according to the following guide. 5-4. IN THE AUX FUNCTION 5-4-1. Solution Please check and replace IC202 on MAIN board. 5-4-2. How to troubleshoot (Countermeasure) 1) Check AUX_L/R signals to IC202 (Pin29, 30).
  • Page 42 ONE POINT REPAIR GUIDE NO SOUND There is no sound output in the TUNER FUNCTION, repair the set according to the following guide. 5-5. IN THE TUNER FUNCTION 5-5-1. Solution Please check and replace IC202, TU200 on MAIN board. 5-5-2. How to troubleshoot (Countermeasure) 1) Check if TUNER_LR is entered from Pin1, 3 of TU200 to IC202(Pin27, 28).
  • Page 43 ONE POINT REPAIR GUIDE NO SOUND There is no sound output in the PORTABLE FUNCTION, repair the set according to the following guide. 5-6. IN THE PORTABLE FUNCTION 5-6-1. Solution Please check and replace IC202 on MAIN board. 5-6-2. How to troubleshoot (Countermeasure) 1) Check PT_L/R signals to IC202 (Pin1, 2).

  • Page 44: Electrical Troubleshooting Guide

    ELECTRICAL TROUBLESHOOTING GUIDE 1. POWER (SMPS) No 5.6 VA F901 normal? Replace F901 (Use the same fuse). BD901 normal? Replace BD901. TH901(TH903) normal? Replace TH901. Is Vcc (10 V ~ 18 V) supplied to D902 normal? IC901 pin7? Check or replace D902. D933 normal? Replace D933.
  • Page 45 ELECTRICAL TROUBLESHOOTING GUIDE No PVDD F901 normal? Replace F901 (Use the same fuse). BD901 normal? Replace BD901. TH901(TH903) normal? Replace TH901. Is Vcc (10 V ~ 18 V) supplied to D903 normal? IC911 pin4? Check or replace D903. Q901 base “H”? •...
  • Page 46 ELECTRICAL TROUBLESHOOTING GUIDE No 12 V Is Vcc (15 V) Check or replace D935. supplied to IC931? IC931 pin4 “H”? Check P-CTRL “H” signal from MCU. Check or replace IC931. No VFD Check or replace D931. D931 normal? ZD931 normal? Check or replace ZD931.

  • Page 47: Mcs Part Check

    ELECTRICAL TROUBLESHOOTING GUIDE 2. MCS PART CHECK MCS PART CHECK Check if voltage of CN102 Refer to SMPS troubleshooting. Pin13, 14 is 12 VA. Check if IC100 Check and change IC100. have 3.3 VA output. Check if IC101 Check and change IC101. have 1.2 VA output.

  • Page 48: Fld Display Check

    ELECTRICAL TROUBLESHOOTING GUIDE 4. FLD DISPLAY CHECK FLD DISPLAY CHECK Check CN102 Pin13,14 input Refer to SMPS troubleshooting. voltage. Check if both end voltage of F+, F- are over 1.85 V VH : over 27 V. Check CN300 connection and Check CN300 connection.

  • Page 49: Pwm Modulation Check

    ELECTRICAL TROUBLESHOOTING GUIDE 5. PWM MODULATION CHECK PWM MODULATION PART CHECK Check Refer to CN102 Pin13, 14 SMPS troubleshooting. (12 VA) • Check IC700(TAS5548) VDD 3.3 V - Pin9,14.35,50. • Check X700 (12.288 MHz). Check Check X700 Replace X700(12.288 MHz). X700(12.288 MHz) (12.288 MHz).

  • Page 50: Power Amp Part Check

    ELECTRICAL TROUBLESHOOTING GUIDE 6. POWER AMP PART CHECK POWER AMP PART CHECK Check Refer to SMPS troubleshooting. CN102 Pin13, 14: +12 VA Pin5, 6, 7 : 36 V. Check IC701, IC702 Pin29, 30, 31, 36, 37, 38 input voltage. Check IC701, IC702 Check each line resistor output voltage.

  • Page 51: Tuner / Aux Function Check

    ELECTRICAL TROUBLESHOOTING GUIDE 7. TUNER / AUX FUNCTION CHECK FUNCTION CHECK Check IC202 Check JK200,TU200. (PCM1865) Pin27, 28, 29, 30 input. Check Check IC202 IC202 Pin8: ADC +3.3 V Check CN102 Pin13,14: 12 VA. (PCM1865) Pin18, 19 Pin13,14,25: DVCC output data. +3.3 V.

  • Page 52: Cd Function

    ELECTRICAL TROUBLESHOOTING GUIDE 9. CD FUNCTION CD FUNCTION Is Motor_open/close OK? Can the Is load +,- ok? (IC400 Pin9,10) disc insert? Check IC400. Is Motor ok? (about 12 Ω) Check loading motor. Check IC400 (Motor drive IC). Focus, IM driving Disc reading tracking, sled signal (Focus and tracking) is ok?

  • Page 53: Double Usb Function

    ELECTRICAL TROUBLESHOOTING GUIDE 10. DOUBLE USB FUNCTION USB FUNCTION Plug-in USB device. Check CON301. Display “NO USB”. Check USB_5 V. Check USB jack Check USB_D-/D+ Display “READ”. (JK301/ JK302). (R383, 384). Check IC500 Display “NO FILE”. Replace IC500. (Pin U7, U8/ A7, A8). Check USB audio file in USB device (MP3, WMA file is playable) 3-26...

  • Page 54: Waveforms Of Major Check Point

    WAVEFORMS OF MAJOR CHECK POINT CD-16 M DATA ADDRESS Fig 1. SDRAM Fig 2. SERVO ① ② IC504 pin38, IC504 pin53 ⑤ IC500 pin M1 ③ ④ IC504 pin35, IC504 pin19 MCS_MCLK CD_BCK MCS_BCK CD_LRCK MCS_LRCK CD_DATA ADC_DATA Fig 3-1. AUDIO PATH Fig 3-2.
  • Page 55 3-28...

  • Page 56: Wiring Diagram

    WIRING DIAGRAM C J65 : 80 X 80 C J45 : 60 X 60 C C J65 O pt i on AUX In Tuner C J44 : N ot appl y IC204 LED Driver IC202 IC401 IC500 RF IC SMPS IC504 IC400 SDRAM...

  • Page 57: Block Diagrams

    BLOCK DIAGRAMS 1. SYSTEM BLOCK DIAGRAM ANALOG INPUT Block Block PWM + AMP Block [CJ65 : Total 2hch 900W] [[CJ45: Total 2.1ch 720W 240+240+240] [CJ44 : Total 2ch 460W] FRONT Block 3-31 3-32...

  • Page 58: Smps Block Diagram

    2. SMPS BLOCK DIAGRAM 3-33 3-34...

  • Page 59: Power Block Diagram

    3. POWER BLOCK DIAGRAM SMPS 3-35 3-36...

  • Page 60: Circuit Voltage Chart

    CIRCUIT VOLTAGE CHART 1. INPUT VOLTAGE OF ICs 2. INPUT VOLTAGE OF CONNECTORS 3. VOLTAGE OF CAPACITORS Location No. Pin No. SPEC [V] Test [V] Pin Name Spec. Range [%] Test Block Location No. Spec. Test IC100 Pin No MAIN(CN902) <-> SMPS (CN102) C121 220 uF / 10 V 3.06...

  • Page 61: Printed Circuit Board Diagrams

    PRINTED CIRCUIT BOARD DIAGRAMS 1. SMPS P.C.BOARD DIAGRAM (TOP VIEW) (BOTTOM VIEW) NOTE) Warning Parts that are critical with respect to risk of fire or electrical shock. 3-39 3-40...

  • Page 62: Main P.c.board

    2. MAIN P.C.BOARD DIAGRAM (TOP VIEW) (BOTTOM VIEW) 3-41 3-42...

  • Page 63: Front P.c.board

    3. FRONT P.C.BOARD DIAGRAM (TOP VIEW) (BOTTOM VIEW) 3-43 3-44...

  • Page 64: Mic P.c.board Diagram

    4. MIC P.C.BOARD DIAGRAM (TOP VIEW) (BOTTOM VIEW) 3-45 3-46...
  • Page 65 3-47 3-48...

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