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LG SJ8 Service Manual

LG SJ8 Service Manual

Smart hi-fi audio wireless multi-room sound bar
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CONFIDENTIAL
SMART Hi-Fi AUDIO
Wireless Multi-room Sound Bar
SERVICE MANUAL
MODEL: SJ8
(SJ8, SPJ8B-W)
CAUTION
BEFORE SERVICING THE UNIT, READ THE "SAFETY PRECAUTIONS"
IN THIS MANUAL.
P/NO : AFN78212019
SEPTEMBER, 2017
Copyright © 2017 LG Electronics Inc. All rights reserved.
Only for training and service purposes.

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  • Page 1 Wireless Multi-room Sound Bar SERVICE MANUAL MODEL: SJ8 (SJ8, SPJ8B-W) CAUTION BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS” IN THIS MANUAL. P/NO : AFN78212019 SEPTEMBER, 2017 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 2 CONTENTS SECTION 1 ..SUMMARY SECTION 2 ..CABINET & MAIN CHASSIS SECTION 3 ..ELECTRICAL SECTION 4 ..WIRELESS SUBWOOFER PART Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 3: Table Of Contents

    NAME OF EACH COMPONENT ........................1-5 WIRELESS SUBWOOFER CONNECTION ....................... 1-6 HIDDEN MODE ..............................1-7 SOFTWARE UPDATE GUIDE ........................... 1-8 VERSION CHECK ............................1-16 SPECIFICATIONS ............................1-17 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 4: Product Safety Servicing Guidelines For Audio Products

    When servicing this product, under no circumstances should the original design be modified or altered without permission from LG Corporation. All components should be replaced only with types identical to those in the original circuit and their physical location, wiring and lead dress must conform to original layout upon completion of repairs.

  • Page 5: Servicing Precautions

    Note 1: Accessible Conductive Parts include Metal panels, tricity sufficient to damage an ES device.) Input terminals, Earphone jacks,etc. Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 6: Name Of Each Component

    F (Function): E OPTICAL IN connector HDMI IN) F HDMI IN - / + (Volume) G HDMI OUT (TV ARC) : (Wi-Fi): (Add): B DC IN Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 7: Wireless Subwoofer Connection

    2. Turn on the main unit. 3. Pairing is completed. - The green LED on the rear of the wireless subwoofer turns on. Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 8: Hidden Mode

    Main unit “MIN” (volume minimum state) + Remote control ' (Mute)' for about 5 seconds. Woofer RX Reset ‘RESET’ on the woofer for 3 seconds. MICOM Version BE Version Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 9: Software Update Guide

    2) Insert USB to USB port. 3) VFD display “UPGRADE”. 4) Press “PLAY/PAUSE” key. 5) VFD display “EQUPDATE”. 6) Set auto power off after fi nished the updating. Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 10 Power on Smart Audio and implement Music Flow App in your smart phone. 1) Connect Speaker. 2) Select red box. 3) Settings -> Version Info. 4) Select Version info. Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 11 fi rmware in the server. if you press “Need to update”. 6) Start Update below icon. ※ Display update progress info. ※ Do not power off during update. 1-10 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 12 Using APP 7) Display update info. 8) Display “Update is completed” message when Complete update. 1-11 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 13 3. Using MP tool 1) Open MP tool and select “Key DN”. 2) Check the section for download and open download fi le. 1-12 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 14 ※ Caution : Do not you update the B/E program and MICOM program at the same time. 6) Connect Status change “OK!” if success connect MP tool. 1-13 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 15 Using MP tool 7) Press “Update” button. 8) Download result display “OK!” if start download. 1-14 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 16 Using MP tool 9) You can identify update status by network indicator lamp. White <Updating : blinking white LED> 1-15 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 17: Version Check

    10.168.0.1 2) Open MP tool. 3) Set power on. 4) Press “ADD” button after connect LAN cable. 5) Display the version in the tool. 1-16 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 18: Specifications

    Integrated IEEE 802.11n (Draft 2.0) wireless networking access, compatible with 802.11a/b/g/n Wi-Fi networks. • Designs and specifications are subject to change without prior notice. 1-17 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 19 1-18 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 20 2. HOW TO DISASSEMBLE THE SUBWOOFER ..................2-9 EXPLODED VIEWS ............................2-13 1. MAIN UNIT SECTION ..........................2-13 2. WIRELESS SUBWOOFER SECTION ....................2-15 3. PACKING ACCESSORY SECTION ....................... 2-17 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 21: Disassembly Instructions

    ※ Before begin, position the Main Unit upside down. 1-1. Case Bottom Assembly 1) Remove the 24 screws 2) Remove the Case Bottom Assembly. Case Bottom Assembly Figure 1-1 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 22: How To Disassemble The Main Unit

    1) Disconnect the 3 harness cables from the Main PCB Assembly. Figure 1-2 (1) 2) Remove the screw. 3) Remove the Main Frame Assembly (Main Chassis + PCBA). Main Frame Assembly Figure 1-2 (2) Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 23 2) Disconnect the cables from the Main PCB. 3) Remove the 5 Screws (Main + HDMI Jack). 4) Remove the Main PCB Assembly. Main Chassis Main PCB Assembly Figure 1-2-2 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 24 3) Disconnect the FFC cable from the WIRELESS module. 4) Remove the BT module. 5) Disconnect the FFC cable from the BT module. WIRELESS Module BT Module Figure 1-2-3 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 25 4) Remove the Holder 5) Disconnect the 2 Hooks. 6) Remove the WI-FI module. 7) Disconnect the FFC cable from the WI-FI module. WI-FI Module Figure 1-2-4 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 26 Speaker Chamber Left Assembly Figure 1-3 1-4. KEY PCB Assembly 1) Remove the 2 screws. 2) Remove the KEY PCB Assembly. KEY PCB Assembly Figure 1-4 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 27 Figure 1-5 (1) < Harness cable from KEY PCB to MAIN PCB > Figure 1-5 (2) < Speaker network cable from SPK Chamber L/R Assembly to MAIN PCB > Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 28 1) Remove the 13 screws. Figure 2-1 (1) 2) Pull out the Rear Panel Assembly and disconnect the SPK cable. Rear Panel Assembly SPK cable Figure 2-1 (2) Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 29: How To Disassemble The Subwoofer

    2) Assemble the WIRELESS module into the wireless holder. 3) Attach the EVA sheet (0.15T) to the WIRELESS module. 4) Connect the FFC cable. Figure 2-2 (2) 2-10 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 30 1) Disconnect the Power inlet socket cable. AMP+SMPS PCB Assembly Figure 2-3 (1) 2) Remove the 5 screws. 3) Remove the AMP+SMPS PCB Assembly. AMP+SMPS PCB Assembly Figure 2-3 (2) 2-11 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 31 2-12 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 32: Exploded Views

    EXPLODED VIEWS 1. MAIN UNIT SECTION A80R MAIN Wi-Fi CABLE1 CABLE4 FRONT CABLE3 A80L WIRELESS LCD01 CABLE2 2-13 2-14 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 33: Wireless Subwoofer Section

    2. WIRELESS SUBWOOFER SECTION A900 A900W A45W A54W 2-15 2-16 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 34: Packing Accessory Section

    836 Screws (2) 835 Wall bracket 837 Cover foot 829 Cable tie (3) 900 Remote control 808 Batteries (2) 803 Main packing 804 Bag 802 Box 2-17 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 35 2-18 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 36 1. MAIN P. C. BOARD DIAGRAM ......................3-23 2. AMP P. C. BOARD DIAGRAM ......................3-25 3. FRONT P. C. BOARD DIAGRAM ......................3-27 4. KEY P. C. BOARD DIAGRAM ......................3-27 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 37: Wiring Diagram

    WIRING DIAGRAM Ethernet Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 38: Block Diagrams

    BLOCK DIAGRAMS 1. SYSTEM BLOCK DIAGRAM OP_MUTE DAC_RST SCL/DSA/CS DSP_I2S Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 39: Power Block Diagram

    2. POWER BLOCK DIAGRAM Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 40: One Point Repair Guide

    3) If 25 VA is OK, but 12 VA is abnormal pin3 of IC380 (VOUT), replace AMP board. 1-1-3. Service hint (Any picture / Remark)         < AMP board top view > Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 41 3) If 5.1 VA is OK, replace FRONT board. 1-2-3. Service hint (Any picture / Remark)       IC303 IC303   < MAIN board top view > Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 42 1-3-3. Service hint (Any picture / Remark)                 CNF51 CNF51 < MAIN board top view > Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 43: Sound

    3) If it still doesn’t work, replace MAIN board. 2-1-3. Service hint (Any picture / Remark)       CN204 CN204   < MAIN board top view > Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 44 3) If signal is abnormal, replace MAIN Board. 2-2-3. Service hint (Any picture / Remark)     JK201 JK201     < MAIN board top view > Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 45 2) If soldering status and 5.1 VA are abnormal, replace MAIN board. 2-3-3. Service hint (Any picture / Remark)     IC803 IC803 < MAIN board bottom view > 3-10 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 46 2) If 5.1 VA is OK, but DAC_3.3V is abnormal IC382 pin6 (VOUT), replace MAIN board. 2-4-3. Service hint (Any picture / Remark)       IC382 IC382   < MAIN board top view > 3-11 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 47 2) If DAC_3.3V is OK, but DAC_1.2V is abnormal IC383 pin5 (VOUT), replace MAIN board. 2-5-3. Service hint (Any picture / Remark)     IC383 IC383     < MAIN board top view > 3-12 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 48: Protection Error

    3) If OP_AMP out is OK and speaker out (FL+/-, FR+/-, TWL+/-, TWR+/-) has DC voltage, replace AMP board. 3-1-3. Service hint (Any picture / Remark) CN701 CN701 CN702 CN702 < AMP board top view > 3-13 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 49 2) If speaker unit is OK, replace AMP board. 3-2-3. Service hint (Any picture / Remark) CN701 CN701 CN702 CN702 < AMP board top view > 3-14 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 50: Waveforms Of Major Check Point

    WAVEFORMS OF MAJOR CHECK POINT 1. CRYSTAL Fig 1-1. Crystal Fig 1-2. Crystal X501 (27 MHz) X801 (27 MHz) 3-15 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 51 CRYSTAL Fig 1-3. Crystal Fig 1-4. Crystal X260 (12.288 MHz) X700 (40 MHz) 3-16 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 52: Flash

    Press Power Key About : 1.35 V Fig 3-2. Tact Key Press FUNC Key About : 1.09 V Fig 3-3. Tact Key Press VOL(-) Key 3-17 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 53 Press No Key About : 0.45 V Fig 3-5. Tact Key Press Wi-Fi Key About : 0 V Fig 3-6. Tact Key Press ADD Key 3-18 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 54: Remote Control

    “ Low” Timing 4.4 ms 3.6 ms ~ 5.04 ms “ High” Timing 4.48 ms 4.08 ms ~ 5.04 ms Fig 4-2. Remote Control High Timing 3-19 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 55: Optical

    5. OPTICAL Fig 5-1. Optical Fig 5-2. Optical Opt In Opt Det 3-20 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 56: Circuit Voltage Chart

    18, 19, 31, 32 PVCC 4.5 V ~ 26 V 25.13 V IC801 IC,Serial Flash Memory 2.7 V ~ + 3.6 V ++3.342 V 3-21 3-22 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 57: Printed Circuit Board Diagrams

    PRINTED CIRCUIT BOARD DIAGRAMS 1. MAIN P. C. BOARD DIAGRAM (TOP VIEW) (BOTTOM VIEW) 3-23 3-24 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 58: Amp P. C. Board Diagram

    2. AMP P. C. BOARD DIAGRAM (TOP VIEW) (BOTTOM VIEW) 3-25 3-26 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 59: Front P. C. Board Diagram

    3. FRONT P. C. BOARD DIAGRAM (TOP VIEW) (BOTTOM VIEW) 4. KEY P. C. BOARD DIAGRAM (TOP VIEW) (BOTTOM VIEW) 3-27 3-28 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 60 6. LED ............................... 4-11 CIRCUIT VOLTAGE CHART ........................... 4-13 PRINTED CIRCUIT BOARD DIAGRAMS ....................... 4-15 1. WOOFER SMPS & AMP P. C. BOARD ....................4-15 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 61: Wiring Diagram

    WIRING DIAGRAM 2P, 3.96mm ST, Non Lock SMD Wireless 26P, 0.5mm ST, Non Lock SMD 2P, 3.96mm ST, Non Lock , SMD Power Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 62: Block Diagram

    BLOCK DIAGRAM Wireless LED (RED, GREEN) Wireless AMP_PDN AMP_SD PAIRING Reset KEY SW+/SW- PWM IC AMP IC Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 63: One Point Repair Guide

    If you can’t check 12 VA voltage, refer to the step 1-1. WL707 WL707 WIC705 WIC705 < Woofer SMPS & AMP board top view > Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 64 3) 1), 2) is NG  Replace WIC703. If you can’t check PVDD voltage, then replace the PCB board. WIC703 WIC703 < Woofer SMPS & AMP board bottom view > Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 65: Wireless Connection

     The main set and the wireless subwoofer are factory reset mode, then power on. WFB604 WFB604 Wireless module Wireless module Connection check Connection check < Woofer SMPS & AMP board top view > Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 66: Waveforms Of Major Check Point

    WAVEFORMS OF MAJOR CHECK POINT 1. CRYSTAL FIG 1. WX601 (24.576 MHz) 2. FLASH MEMORY FIG 2. VCC, CS#, CLK, DO Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 67: Voltage

    3. VOLTAGE FIG 3-2. Woofer 12 VA FIG 3-1. Woofer PVDD FIG 3-3. Woofer 3.3 VA FIG 3-4. Woofer 3.3V_PWM Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 68: Amp Voltage

    4. AMP VOLTAGE FIG 4-2. AMP_12V FIG 4-1. AMP PVDD Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 69: Pwm

    5. PWM FIG 5-2. Woofer PWM SW- Signal FIG 5-1. Woofer PWM SW+ Signal 4-10 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 70: Led

    6. LED FIG 6-2. Pairing On Status  Green LED FIG 6-1. Pairing Off Status  Red LED 4-11 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 71 4-12 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 72: Circuit Voltage Chart

    12.52 V 12.52 V 4.5 V ~ 17 V WIC705 DC,DC Converter VOUT: SW: #2 3.42 V 3.42 V 0.76 V ~ 7 V 4-13 4-14 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 73: Printed Circuit Board Diagrams

    1. WOOFER SMPS & AMP P. C. BOARD (TOP VIEW) (BOTTOM VIEW) NOTE) Warning Parts that are critical with respect to risk of fire or electrical shock. 4-15 4-16 Copyright © 2017 LG Electronics Inc. All rights reserved. Only for training and service purposes.

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