LG SN4A Service Manual
  1. Manuals
  2. Brands
  3. LG Manuals
  4. Speaker System
  5. SN4A
  6. Service manual

LG SN4A Service Manual

Wireless sound bar
Hide thumbs Also See for SN4A:
Table of Contents

Advertisement

Quick Links

Download this manual
Wireless Sound Bar
SERVICE MANUAL
MODEL: SN4A
(SN4A, SPN4BM-W)
CAUTION
BEFORE SERVICING THE UNIT, READ THE "SAFETY PRECAUTIONS"
IN THIS MANUAL.
P/NO : AFN30064620
JULY, 2021
"Any reproduction, duplication, distribution (including by way of email, facsimile or other
electronic means), publication, modification, copying or transmission of this Service Manual is
STRICTLY PROHIBITED unless you have obtained the prior written consent of the LG Electronics
entity from which you received this Service Manual. The material covered by this prohibition includes,
without limitation, any text, graphics or logos in this Service Manual."
Copyright © 2021 LG Electronics Inc. All rights reserved.
Only for training and service purposes.

Advertisement

Table of Contents
loading

Related Manuals for LG SN4A

Summary of Contents for LG SN4A

  • Page 1 Service Manual is STRICTLY PROHIBITED unless you have obtained the prior written consent of the LG Electronics entity from which you received this Service Manual. The material covered by this prohibition includes, without limitation, any text, graphics or logos in this Service Manual.”...
  • Page 2 CONTENTS SECTION 1 ..GENERAL SECTION 2 ..CABINET & MAIN CHASSIS SECTION 3 ..ELECTRICAL SECTION 4 ..WIRELESS SUBWOOFER PART Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 3: Table Of Contents

    • ELECTROSTATICALLY SENSITIVE (ES) DEVICES LOCATION OF CUSTOMER CONTROLS ......................1-5 WIRELESS SUBWOOFER CONNECTION ....................... 1-6 HIDDEN KEY MODE ............................1-7 SOFTWARE UPDATE GUIDE ........................... 1-8 SPECIFICATIONS ............................1-15 Copyright © 2021 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 © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 6: Location Of Customer Controls

    - Connect HDMI IN jack on the back of the unit - Connect USB memory device to the USB port to HDMI OUT jack on the external device. on the back of the unit. Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 7: Wireless Subwoofer Connection

    PAIRING.) 2. Turn on the sound bar. - Pairing is completed. The yellow - green LED on the front of the wireless subwoofer turns on. Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 8: Hidden Key Mode

    Main unit 'VOL-' + Remote Control ' EEPROM CLEAR (Initialize) Main unit 'VOL-' + Remote Control ' VERSION CHECK Main unit 'VOL-' + Remote Control 'Play/Pause' Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 9: Software Update Guide

    Version Check Caution : • Take care not to power off during update. • Do format USB memory before update (FAT32 fi le system). Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 10 Check VFD what module is in progress one by one. ※ The numbers in VFD display of wireless modules will increase in progress as progress percent from 00 to 100. Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 11 Boot loader T1910310 Touch 00 75 05 93 ... Option <SN4 VFD Display in Version Display> 3) Compare the version VFD shows and you updated. 1-10 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 12 Step 3. Execute “Music Flow Bluetooth” App. Step 4. Connect between android device and SN4 main unit by “Music Flow Bluetooth” App.   1-11 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 13 Current version and Latest version in pop up window “Device version info.” are same. Also update icon must be disabled.   1-12 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 14 3) SN4 main unit executes update. 1) Download binary 2) Transfer to SN4 3) Update progress “Music Flow Bluetooth” D-UP DNLD VFD Model Current Function M-UP 1-13 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 15 Step 10. Power on SN4 main unit again. Step 11. Check the current versions to verify whether the update was successfully completed in such a way of Step 5.~ 6. 1-14 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 16: Specifications

    Dimensions (W x H x D) Approx. 171 mm x 390 mm x 261 mm • Designs and specifications are subject to change without prior notice. 1-15 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 17 1-16 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 18 1. HOW TO DISASSEMBLE THE MAIN UNIT ..................... 2-2 EXPLODED VIEWS ............................2-7 1. MAIN UNIT SECTION ..........................2-7 2. WIRELESS SUBWOOFER SECTION ....................2-11 3. PACKING ACCESSORY SECTION ....................... 2-15 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 19: Disassembly Instructions

    DISASSEMBLY INSTRUCTIONS 1. HOW TO DISASSEMBLE THE MAIN SET 1) Remove the 19 screws. Figure 1-1 2) Remove the Case Bottom Assembly. Figure 1-2 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 20: How To Disassemble The Main Unit

    3) Remove the 2 screws, Disconnect the Harmess/FFC cables (KEY, SPK) and Remove the Main PCB Assembly.  Figure 1-3 4) Remove the SPK Chamber L/R Assembly.   Figure 1-4 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 21 HOW TO DISASSEMBLE THE MAIN SET 5) Remove the L/R Deco Assembly. Figure 1-5 6) Remove the 4 screws and Disconnect FFC cables (BT, Wireless). Wireless Figure 1-6 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 22 HOW TO DISASSEMBLE THE MAIN SET 7) Remove the EMI Shield Tape. Figure 1-7 8) Remove the EMI Shield Tape of Bottom side. Figure 1-8 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 23 HOW TO DISASSEMBLE THE MAIN SET 9) Disassembly fi nish. Figure 1-9 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 24: Exploded Views

    EXPLODED VIEWS 1. MAIN UNIT SECTION A80R MAIN CABLE1 A80L CABLE2 CABLE3 WIRELESS Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 25 LCD Module SMMD3276-A-00-VTNF-WX BACK LIG CABLES CABLE1 EAD65485502 Harness,Single CAV-18-39 SMH200-02 to SMH200- CABLE2 EAD62185618 Cable,FFC AT05012105D01 105MM 0.50MM 12P CABLE3 EAD62131522 Cable,FFC 26P005D-H2-1F01A-T-143-64-79-0 2-10 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 26: Wireless Subwoofer Section

    EQUILATERAL TRIANGLE IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN SERVICE LITERATURE. A900 CN901 A47W SMPS A54W WIRELESS A45W 2-11 2-12 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 27 MCZ63611901 Duct CUTTING PAPER SPK S55A1-D OTHE MCZ63631801 Duct MOLD HIPS SPK S45A1-D MOLD INN EAD62131520 Cable,FFC 26P005D-H2-1FS-N-90-90-0-0-0-0 EAD60771803 Harness,Single HIT-501-LG16 RT5503202(RING) R 2-13 2-14 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 28: Packing Accessory Section

    806 Optical cable 833 AC adapter 900 Remote control 300 Power cord (Main unit) 300W Power cord (Woofer) 835 Wall bracket 836 Screws (2) Copyright © 2021 LG Electronics Inc. All rights reserved. 2-15 Only for training and service purposes.
  • Page 29 Accessory Assembly AGG75620751 Packing Assembly LAS550H silver new screw + bag AKB75595361 Remote Controller Assembly MA6 SN/SL10/9/8/7/6/5/4 (Add AKB75595331 Remote Controller Assembly MA6 SM/SL10/9/8/7/6/5/4 Soundb Copyright © 2021 LG Electronics Inc. All rights reserved. 2-16 Only for training and service purposes.
  • Page 30 CIRCUIT VOLTAGE CHART ........................... 3-33 PRINTED CIRCUIT BOARD DIAGRAMS ....................... 3-35 1. MAIN P. C. BOARD DIAGRAM ......................3-35 2. KEY P. C. BOARD DIAGRAM ......................3-37 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 31: Wiring Diagram

    WIRING DIAGRAM HDMI HDMI 26 PIN FFC CABLE 14 PIN FFC CABLE JK300 DC JACK 2 PIN HARNESS CN704 CN703 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 32: Block Diagrams

    BLOCK DIAGRAMS 1. SYSTEM BLOCK DIAGRAM Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 33: Power Block Diagram

    2. POWER BLOCK DIAGRAM Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 34: One Point Repair Guide

    L302 10UH EN/SYNC (1%) R335 100K DGND DGND C306 R306 100nF DGND DGND VOUT = 0.792x((47K/3.3K)+1)= 12.072V IC302 IC302 < MAIN board top view > Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 35: Booting When You Turn The Unit On, No Message Or "Hello" On Front Panel

    1uF (1) /16V /16V /16V (1%) DGND DGND R310 R302 (1%) DGND DGND VOUT = 0.798x((62K+8.2K)/13K+1)= 5.107V IC305 IC305 < MAIN board bottom view > Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 36 R309 240K 100nF (1%) (1%) (1%) VOUT = 0.6*(1+R1/(R2//R3)) DGND VOUT = 0.6*(1+100K/((24K*240K)/(24K+240K))) = 0.6*(1+100K/21.82K) = 3.350V IC301 IC301 < MAIN board top view > Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 37 C156 2.2uF VB1+ 2.2uF VB1+ /10V(X5R) /10V(X5R) VB0+ DGND VB0- C132 VLCD 0.33uF VLCD R193 CN101 DGND CN101 CN101 < MAIN board top view > Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 38: Sound

    FL101 NC 10pF 10pF DGND TB10 RESET BT_RESET TB11 BT_WAKEUP BT_WAKEUP TB12 MCU_STBY MCU_STBY ZD103 Z02W3.9V DGND CN102 CN102 < MAIN board top view > Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 39 MPEG OPT_IN R201 MICOM OPT_DET C207 C208 15pF C224 100pF DGND DGND C208 C208 R209 R209 JK202 JK202 < MAIN board top view > Copyright © 2021 LG Electronics Inc. All rights reserved. 3-10 Only for training and service purposes.
  • Page 40 C361 C362 C363 C399 EN/ENB 10uF 10uF 10uF 100nF C360 R383 4.7K DGND DGND DGND HDMI_CTRL IC308 IC308 < MAIN board top view > Copyright © 2021 LG Electronics Inc. All rights reserved. 3-11 Only for training and service purposes.
  • Page 41 R210 USB D- USB1_DN MPEG R211 USB D+ USB1_DP USB_GND DGND C206 C205 10pF 10pF DGND JK201 JK201 < MAIN board bottom view > Copyright © 2021 LG Electronics Inc. All rights reserved. 3-12 Only for training and service purposes.

  • Page 42: Protection Error

    3) If PWM IC out is ok and speaker out (FL+/-, FR+/-, TWL+/-, TWR+/-) has DC voltage, replace MAIN board. 3-1-3. Service hint (Any picture / Remark) AR601 AR601 CN703 CN703 IC600 IC600 AR602 AR602 CN704 CN704 < MAIN board top view > Copyright © 2021 LG Electronics Inc. All rights reserved. 3-13 Only for training and service purposes.
  • Page 43 2) If 12 V is OK, replace MAIN board. 3-2-3. Service hint (Any picture / Remark) IC701 IC701 IC700 IC700 < MAIN board bottom view > Copyright © 2021 LG Electronics Inc. All rights reserved. 3-14 Only for training and service purposes.

  • Page 44: Electrical Troubleshooting Guide

    Check F301 Voltage 25 VA Check R371 Voltage 12 VA Replace IC302 Replace IC305 Check FB305 Voltage 5.1 VA Check R373 Voltage 3.3 VA Replace IC301 Copyright © 2021 LG Electronics Inc. All rights reserved. 3-15 Only for training and service purposes.
  • Page 45 Check F301 Voltage 25 VA Check R371 Voltage 12 VA Replace IC302 Replace IC305 Check FB305 Voltage 5.1 VA Check R374 Voltage 1.5 V Replace IC303 Copyright © 2021 LG Electronics Inc. All rights reserved. 3-16 Only for training and service purposes.
  • Page 46 Check F301 Voltage 25 VA Check R371 Voltage 12 VA Replace IC302 Replace IC305 Check FB305 Voltage 5.1 VA Check R376 Voltage 1.2 V Replace IC311 Copyright © 2021 LG Electronics Inc. All rights reserved. 3-17 Only for training and service purposes.
  • Page 47 Check F301 Voltage 25 VA Check R371 Voltage 12 VA Check IC302 Check Q301 change Check R377 Check Q301 2pin Voltage 12 V Voltage 12 V Copyright © 2021 LG Electronics Inc. All rights reserved. 3-18 Only for training and service purposes.
  • Page 48 Check F301 Voltage 25 VA Check R371 Voltage 12 VA Replace IC302 Replace IC305 Check FB305 Voltage 5.1 VA Check R378 Voltage 5 V Replace IC306 Copyright © 2021 LG Electronics Inc. All rights reserved. 3-19 Only for training and service purposes.
  • Page 49 Check F301 Voltage 25 VA Check R371 Voltage 12 VA Replace IC302 Replace IC305 Check FB305 Voltage 5.1 VA Check C361 Voltage 3.3 V Replace IC308 Copyright © 2021 LG Electronics Inc. All rights reserved. 3-20 Only for training and service purposes.
  • Page 50 Replace IC302 Replace IC305 Check FB305 Voltage 5.1 V A Check R373 Voltage 3.3 VA Replace IC301 Check FB307, FB313 Voltage 3.3 V Replace IC304 Copyright © 2021 LG Electronics Inc. All rights reserved. 3-21 Only for training and service purposes.
  • Page 51 Check R371 Voltage 12 VA Replace IC302 Replace IC305 Check FB305 Voltage 5.1 VA Check R373 Voltage 3.3 VA Replace IC301 Check C311 Voltage 3.3 V Replace IC309 Copyright © 2021 LG Electronics Inc. All rights reserved. 3-22 Only for training and service purposes.
  • Page 52 Check R371 Voltage 12 VA Replace IC302 Replace IC305 Check FB305 Voltage 5.1 VA Check R373 Voltage 3.3 VA Replace IC301 Check C371 Voltage 3.3 V Replace IC310 Copyright © 2021 LG Electronics Inc. All rights reserved. 3-23 Only for training and service purposes.

  • Page 53: Key Part

    Check the connecting cables Voltage 3.3 V Check R111 Pull-up Resistor Replace the Related part. Check SWA01, SWA02, Check RA01, RA04, RA05, RA06 SWA03, SWA04 Copyright © 2021 LG Electronics Inc. All rights reserved. 3-24 Only for training and service purposes.

  • Page 54: Usb Function

    Check R379 Voltage 5.1 V Check IC306 Check JK201 1pin Voltage 5.1 V Replace the Related part. Check Reading OK Check JK201 2pin(D-), 3pin(D+) Copyright © 2021 LG Electronics Inc. All rights reserved. 3-25 Only for training and service purposes.

  • Page 55: Optical Function

    Check JK202 Check R202 Check R549 3.3VA Voltage Refer to Power Part Troubleshooting Check IC501 pin M19 Check R587 Input waveform Replace the related part. Copyright © 2021 LG Electronics Inc. All rights reserved. 3-26 Only for training and service purposes.

  • Page 56: Waveforms Of Major Check Point

    2. FLASH MEMORY 3.3VA IC102 R106 R108 R107 4.7K 4.7K 4.7K SF_CS DGND HOLD# SF_DO SCLK SF_CLK SF_DI R109 DGND FIG 2. VCC, CS#, CLK, DO Copyright © 2021 LG Electronics Inc. All rights reserved. 3-27 Only for training and service purposes.

  • Page 57: Tact Key

    SWA00 SWA01 SWA02 SWA03 SWA04 RESET RST/NMI/SBWTDIO CA00 R117 100nF P6.0/A0 P6.1/A1 R119 DC_DETECT P6.2/A2 POWER WIFI VOL+ VOL- FUNC. R120 P6.3/A3 AMP_CLIP0 DGND Copyright © 2021 LG Electronics Inc. All rights reserved. 3-28 Only for training and service purposes.

  • Page 58: Usb

    FIG 4-3. USB D- USB_5V JK201 USB_5V FB201 R210 USB D- USB1_DN MPEG R211 USB D+ USB1_DP USB_GND DGND C206 C205 10pF 10pF DGND Copyright © 2021 LG Electronics Inc. All rights reserved. 3-29 Only for training and service purposes.

  • Page 59: 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 5-3. High Timing Copyright © 2021 LG Electronics Inc. All rights reserved. 3-30 Only for training and service purposes.

  • Page 60: Optical

    FIG 6-1. OPT IN FIG 6-2. OPT DET OPTICAL 3.3VA JK202 R209 R202 MPEG OPT_IN R201 MICOM OPT_DET C207 C208 15pF C224 100pF DGND DGND Copyright © 2021 LG Electronics Inc. All rights reserved. 3-31 Only for training and service purposes.
  • Page 61 TGND 100nF 10uF /16V /10V(M) Close to pin TGND FB401 PZ1608U221-1R4TF Close to pin C439 10uF /16V /10V(M) TGND TGND FIG 7-3. TUNER AUDIO Copyright © 2021 LG Electronics Inc. All rights reserved. 3-32 Only for training and service purposes.

  • Page 62: Circuit Voltage Chart

    VDDQ: A1, A8, C1, C9, D2 MEMORY E9, F1, H2, H9 IC503 SERIAL FLASH VCC:8 VCC: 2.7 V ~ 3.6 V D_3.3V : 3.34 V MEMORY 3-33 3-34 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 63: Printed Circuit Board Diagrams

    PRINTED CIRCUIT BOARD DIAGRAMS 1. MAIN P. C. BOARD DIAGRAM (TOP VIEW) (BOTTOM VIEW) 3-35 3-36 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 64: Key P. C. Board Diagram

    F R 4 - 2 L 1 . 2 T 2 0 1 8 . 1 2 . 0 7 P C B S I Z E : 4 0 . 6 X 3 0 3-37 3-38 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 65 3-39 3-40 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 66 PRINTED CIRCUIT BOARD DIAGRAMS ....................... 4-15 1. WOOFER SMPS P. C. BOARD ......................4-15 2. WOOFER AMP P. C. BOARD ......................4-17 3. WOOFER KEY P. C. BOARD ....................... 4-17 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 67: One Point Repair Guide

    WIC607 Nearby WC686 Nearby WC686 < Woofer AMP board top view > PVDD PVDD at WCA601 at WCA601 < Woofer AMP board bottom view > Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 68: Power On Error

    PVDD PVDD at pin7 of WIC607 at pin7 of WIC607 3.7 VA 3.7 VA at WL606 at WL606 < Woofer AMP board top view > Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 69 8 of WIC603 3.3V_PWM 3.3V_PWM 3.3V_PWM 3.3V_PWM at WL615 at WL615 at pin5 of WIC605 at pin5 of WIC605 < Woofer AMP board top view > Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 70: Wireless Connection

    Wireless module Wireless module Connection check Connection check < Woofer AMP board top view > Pairing key Pairing key < Woofer KEY board top view > Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 71: Waveforms Of Major Check Point

    WAVEFORMS OF MAJOR CHECK POINT 1. VOLTAGE FIG 1-1. WIC607 3.7 VA FIG 1-2. PWM 3.3 V FIG 1-3. Wireless 3.3 VA Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 72: Amp Voltage

    2. AMP VOLTAGE PVDD: 34.5 V FIG 2-1. Woofer PVDD FIG 2-2. Woofer 12 V Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 73: Pwm

    3. PWM FIG 3-1. Woofer PWM SW+ SIgnal FIG 3-2. Woofer PWM SW- SIgnal Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 74: Led

    4. LED FIG 4-1. Pairing Off Status  Red LED FIG 4-2. Pairing On Status  Yellow LED Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.
  • Page 75 4-10 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 76: Wiring Diagram

    FFC SMD 24 Pin straight Harness 12Pin Connector Harness Cable 12Pin Pairing Key 2Pin Harness DIP 2pin Cable 2Pin SMPS PCB AMP PCB LED CNT Pairing Key 4-11 4-12 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 77: Block Diagram

    BLOCK DIAGRAM PVDD PWM_SW+ WOOFER PWM_SW- WOOFER PWM 3.3 3.7 V PVDD DC-DC 12 V Wireless 3.3 Flash PVDD DC-DC 4-13 4-14 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 78: Printed Circuit Board Diagrams

    1. WOOFER SMPS 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 © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

  • Page 79: Woofer Amp P. C. Board

    2. WOOFER AMP P. C. BOARD (TOP VIEW) (BOTTOM VIEW) 3. WOOFER KEY P. C. BOARD (TOP VIEW) (BOTTOM VIEW) 4-17 4-18 Copyright © 2021 LG Electronics Inc. All rights reserved. Only for training and service purposes.

This manual is also suitable for:

Spn4bm-w

Table of Contents