LG LAS454B Service Manual
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LG LAS454B Service Manual

2.1 ch wireless sound bar
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Internal Use Only
Website http://biz.lgservice.com
2.1 ch Wireless Sound Bar
SERVICE MANUAL
MODEL: LAS454B
(LAS454B, S55A3-D)
CAUTION
BEFORE SERVICING THE UNIT, READ THE "SAFETY PRECAUTIONS"
IN THIS MANUAL.
P/NO : AFN77195019
NOVEMBER, 2015

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  • Page 1 Internal Use Only Website http://biz.lgservice.com 2.1 ch Wireless Sound Bar SERVICE MANUAL MODEL: LAS454B (LAS454B, S55A3-D) CAUTION BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS” IN THIS MANUAL. P/NO : AFN77195019 NOVEMBER, 2015...
  • Page 2 CONTENTS SECTION 1 ..GENERAL SECTION 2 ..CABINET & MAIN CHASSIS SECTION 3 ..ELECTRICAL SECTION 4 ..WIRELESS SUBWOOFER PART SECTION 5 ..REPLACEMENT PARTS LIST...

  • Page 3: Table Of Contents

    SECTION 1 GENERAL CONTENTS ESD PRECAUTIONS ............................1-3 WIRELESS SUBWOOFER CONNECTION ....................... 1-4 HIDDEN KEY MODE ............................1-5 MCS / EQ HIDDEN KEY GUIDE ........................1-6 MCS / EQ PROGRAM UPDATE GUIDE ......................1-7 SPECIFICATIONS ............................. 1-8...

  • 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: Wireless Subwoofer Connection

    WIRELESS SUBWOOFER CONNECTION LED indicator of wireless subwoofer LED Color Status Yellow-green The connection is trying. (Blink) Yellow-green The connection is completed. The wireless subwoofer is in standby mode or the connection is failed. The power cord of wireless (No display) subwoofer is disconnected.

  • Page 6: Hidden Key Mode

    HIDDEN KEY MODE HIDDEN MODE KEYS USB Mode/ UPDATE Main unit ‘- (Volume)’ + Remote control ‘VOL +’ EEPROM EDIT Main unit ‘- (Volume)’ + Remote control ‘CINEMA’ EEPROM CLEAR (Initialize) Main unit ‘- (Volume)’ + Remote control ‘VOICE’ VERSION CHECK Main unit ‘- (Volume)’...

  • Page 7: Mcs / Eq Hidden Key Guide

    MCS / EQ HIDDEN KEY GUIDE 1. Version & Option Check ※ Please connect the Display Jig to the main unit. 1) Power on. 2) Press main unit "-" (volume -) key and remote control STANDARD key during 3 seconds. 3) Check MCS version.

  • Page 8: Mcs / Eq Program Update Guide

    - Do format USB Memory to FAT32 File system. - USB : Update fi le exist only in the USB Memory stick. Ex ) LAS454B :  E:\PG540_FW_LAS454B_Ver.bin (if USB driver is E:\)  E:\EQ_PRG.BIN (if USB driver is E:\) Wireless Tx ...

  • Page 9: Specifications

    SPECIFICATIONS • GENERAL Power requirements 120 V ~ 60 Hz Power consumption 27 W Networked standby : 0.5 W (If all network ports are activated.) Dimensions (W x H x D) Approx. 950 mm x 71 mm x 47 mm (37.4 inch x 2.8 inch x 1.9 inch) Net Weight Approx.
  • Page 10 SECTION 2 CABINET & MAIN CHASSIS CONTENTS EXPLODED VIEWS ............................2-3 1. MAIN SET SECTION ..........................2-3 2. WIRELESS SUBWOOFER SECTION ...................... 2-5 3. PACKING ACCESSORY SECTION ......................2-7...

  • Page 12: Exploded Views

    EXPLODED VIEWS 1. MAIN SET SECTION NOTES) THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIANGLE IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT A44B SAFETY INFORMATION IN SERVICE LITERATURE. CABLE5 SMPS CABLE3 A44A MAIN FRONT CABLE2 CABLE1 CABLE4 WIRELESS...

  • Page 13: Wireless Subwoofer Section

    2. WIRELESS SUBWOOFER 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. A900 A900W CN901 A47W SMPS A49W A54W A45W WIRELESS 300W...

  • Page 14: Packing Accessory Section

    3. PACKING ACCESSORY SECTION 801 Owner’s manual 806 Optical cable 900 Remote control 808 Batteries (2) 835 Wall bracket 804 Bag 803 Packing, Main 802 Box...
  • Page 16 SECTION 3 ELECTRICAL CONTENTS ONE POINT REPAIR GUIDE ..........................3-2 1. NO POWER PROBLEM (PVDD) ......................3-2 2. POWER ON ERROR ..........................3-3 3. NO SOUND (PORTABLE FUNCTION) ....................3-4 4. NO WIRELESS ............................3-5 5. NO BLUETOOTH ............................ 3-6 6.

  • Page 17: One Point Repair Guide

    ONE POINT REPAIR GUIDE 1. NO POWER PROBLEM (PVDD) No power problem occurs when you power on the unit. 1-1. Solution Replace SMPS board. 1-2. How to troubleshoot (Countermeasure) 1) Check the PVDD voltage 24 V at pin4, 5, 6. When you check the no power at this point, then replace SMPS board.

  • Page 18: Power On Error

    ONE POINT REPAIR GUIDE 2. POWER ON ERROR No display or Not working. 2-1. IC603 1) Check 12 VA at L604. 2) If 12 VA is not checked at the point, then find 24 V at pin7 of IC603. 3) 1), 2) is NG.  Replace IC603. IC603 pin7 IC603 pin7 L604...

  • Page 19: Sound (Portable Function)

    ONE POINT REPAIR GUIDE 3. NO SOUND (PORTABLE FUNCTION) 3-1. Solution Replace IC508 or portable jack (JK502). 3-2. How to troubleshoot (Countermeasure) 1) Please check the soldering status of JK502. 2) Please check L501, L502 (POR_L, POR_R signal) of portable jack (JK502). If you can’t find input signal, replace JK502.

  • Page 20: Wireless

    ONE POINT REPAIR GUIDE 4. NO WIRELESS 4-1. Solution Replace IC505 on MAIN board.(No 3.3 V) 4-2. How to troubleshoot (Countermeasure) 1) Please check externally status of Wireless board to board connection on your eyes. (at CN506 and Wireless module) 2) Please check 3.3 V of WL_3V3 (at L509).

  • Page 21: Bluetooth

    ONE POINT REPAIR GUIDE 5. NO BLUETOOTH 5-1. Solution Replace IC502 on MAIN board.(No 3.3 V) 5-2. How to troubleshoot (Countermeasure) 1) Please check externally status of Bluetooth cable connection on your eyes.(at CN508 and Bluetooth module) 2) Please check 3.3 V of 3.3VA (at L504). If 3.3 V is OK at L504, please check BT_SDA, BT_SCL, BT_RST (pin53, 51, 25) of IC502 and BT_RX, BT_TX (pin29, 27).

  • Page 22: Sound (Optical)

    ONE POINT REPAIR GUIDE 6. NO SOUND (OPTICAL) 6-1. Solution Replace IC507 on MAIN board. 6-2. How to troubleshoot (Countermeasure) 1) Please check 3.3 V of 3.3VA at L503. If you can check 3.3 V, please confirm OPT_DET signal (R5R8) in MAIN board when optical mode. 2) In spite of process 1), set has abnormal output, then replace IC507.

  • Page 23: D(Dc) Protection

    ONE POINT REPAIR GUIDE 7. D(DC) PROTECTION 7-1. Solution Replace IC703 (AMP IC) on MAIN board. 7-2. How to troubleshoot (Countermeasure) 1) After MAIN SET power off, check Red LED blink at intervals of 1 sec. (D Protection or S Protection) 2) Turn MAIN SET power on again.

  • Page 24: S(Shut Down) Protection

    ONE POINT REPAIR GUIDE 8. S(SHUT DOWN) PROTECTION 8-1. Solution Replace IC703 (AMP IC) on MAIN board. 8-2. How to troubleshoot (Countermeasure) 1) After MAIN SET power off, check Red LED blink at intervals of 1 sec. (D Protection or S Protection) 2) Turn MAIN SET power on again.

  • Page 25: B(Burnt) Protection

    ONE POINT REPAIR GUIDE 9. B(BURNT) PROTECTION 9-1. Solution Replace IC703 (AMP IC) on MAIN board. 9-2. How to troubleshoot (Countermeasure) 1) After MAIN SET power off, check Red LED blink at intervals of 0.5 sec. (B Protection) 2) Turn MAIN SET power on again. 3) Check voltage 3.3 V of AMP_PROTECT signal (pin2 of Q701).

  • Page 26: Waveforms Of Major Check Point

    WAVEFORMS OF MAJOR CHECK POINT 1. CRYSTAL FIG 1-1. X501 (24 MHz) FIG 1-2. X502, X701 (24.576 MHz) 3-11...

  • Page 27: Flash Memory

    2. FLASH MEMORY FIG 2. VCC, CS#, CLK, DO 3-12...

  • Page 28: Tact Key

    3. TACT KEY 1 ~ 1.13 V 0.72 ~ 0.82 V FIG 3-2. Press FUNC Key FIG 3-1. Press Power Key 0.424 ~ 0.485 V FIG 3-3. Press VOL - Key FIG 3-4. Press VOL + Key 3-13...

  • Page 29: Usb

    4. USB FIG 4-1. USB_5V FIG 4-2. USB D+ FIG 4-3. USB D- 3-14...

  • Page 30: Remote Control

    5. REMOTE CONTROL FIG 5-1. Input Voltage 15 16 FIG 5-2. Low Timing Item Measured Spec. IR Receiver Spec: Input Level 3.3 V 2.7 ~ 5.5 V “ 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.

  • Page 31: Optical

    6. OPTICAL FIG 6-1. OPT_IN FIG 6-2. OPT_DET 3-16...

  • Page 32: Portable

    7. PORTABLE FIG 7-1. ADC IC 5 V FIG 7-2. ADC IC 3.3 V 1 1 .27 Vrms FIG 7-3. Analog Input Voltage 3-17...
  • Page 33 8. AUDIO PWM (1/2) FIG 8-1. PWM IC 3.3 V FIG 8-2. PWM IC 1.2 V FIG 8-3. BCK FIG 8-4. LRCK 3-18...

  • Page 34: Audio Pwm

    AUDIO PWM (2/2) FL+ FL- FR+ FR- 384.14 kHz 384.17 kHz FIG 8-5. Front L FIG 8-6. Front R 3-19...

  • Page 35: Audio Amp

    9. AUDIO AMP PVDD PVDD: 24 V GVDD AMP_PDN FIG 9-1. AMP IC PVDD FIG 9-2. 3-20...

  • Page 36: Wiring Diagram

    WIRING DIAGRAM Tact Key Front PCB RCU receiver SMD 10pin Main To Front (FFC) Optical DIP 2pin (Power Cord) DIP 6pin B to B (Main to SMPS) Portable SMPS PCB SMD 2pin SMD 3pin Main PCB Audio L Audio R SMD 10pin SMD 26pin Main To BT...

  • Page 37: Block Diagrams

    BLOCK DIAGRAMS 1. SYSTEM BLOCK DIAGRAM 50 W FL_P/N, FR_P/N PWM SDA/SCL POWER/FUNC/VOL+/- (key) TAS5612 PWM RST/MUTE 50 W PS9860 TX_LRCK/BCK/ADATA0 PWM_TX_LRCK/BCK/ADATA2 LFE_P/N AUDIO OUT AMP_FAULT/DC_DET/CLIP0/PROTECT AUDIO IN AMP_PDN(RST) BT_CTS/RTS, BT_SCL/SDA, BT_RST CSR8811 USB D+/D- MLC3730 Flash (4 MB) Flash (1 MB) WL_INT Wireless...

  • Page 38: Power Block Diagram

    2. POWER BLOCK DIAGRAM PVDD 3.3 VA OPTICAL SMPS 3.3 VA (24 V) TAS5612 12 VA VCC_3.3V DCDC Switching CS8422 MP1432 [2.5 A] AVCC_5V PCM1808 12 VA VCC_3.3V DCDC USB (For update) TPS563200 PWM_3.3V PWM PS9860 DCDC USB_1.2VA TPS563200 PLL_1.2VA 1.2 VA 3.3 VA VCC_3.3V...

  • Page 39: Circuit Diagrams

    DESIGN BE MODIFIED OR ALTERED WITHOUT DIFFER FROM THE ACTUAL CIRCUIT USED. THIS 2. Voltages are DC-measured with a digital voltmeter PERMISSION FROM THE LG CORPORATION. ALL WAY, IMPLEMENTATION OF THE LATEST SAFETY during Play mode. COMPONENTS SHOULD BE REPLACED ONLY WITH...

  • Page 40: Main - Dsp Circuit Diagram

    2. MAIN - DSP CIRCUIT DIAGRAM : WAVEFORM NUMBER EAX66789701 Rev1.3(12) MAIN(#2) 2015.07.08 3-29 3-30...

  • Page 41: Main - Interface Circuit Diagram

    3. MAIN - INTERFACE CIRCUIT DIAGRAM INTERFACE : WAVEFORM NUMBER EAX66789701 Rev1.3(12) MAIN(#3) 2015.07.08 3-31 3-32...

  • Page 42: Main - Pwm & Amp Circuit Diagram

    4. MAIN - PWM & AMP CIRCUIT DIAGRAM PWM & AMP : WAVEFORM NUMBER EAX66789701 Rev1.3(12) MAIN(#4) 2015.07.08 3-33 3-34...

  • Page 43: Main - Power Circuit Diagram

    5. MAIN - POWER CIRCUIT DIAGRAM POWER EAX66789701 Rev1.3(12) MAIN(#5) 2015.07.08 3-35 3-36...

  • Page 44: Front Circuit Diagram

    6. FRONT CIRCUIT DIAGRAM 15 16 FRONT : WAVEFORM NUMBER EAX66769801 Rev1.2(5) 2015.07.08 3-37 3-38...

  • Page 45: Circuit Voltage Chart

    CIRCUIT VOLTAGE CHART 1. ICs Designator Description Specifi cation Pin Number Voltage Spec Real Value Main Board IC501, IC505 IC,Serial Flash Memory W25Q80DVSSIG 8MBIT VCC: #8 VCC: 2.7 V ~ 3.6 V VCC: 3.2 V CORE SUPPLY VOLTAGE: VDD12INT: #23 VDD12CORE: #55, #107, #142, #160 VDD12PLL: #87...

  • Page 46: Connectors

    2. CONNECTORS Mearsured Voltage Part Designator Description Specifi cation Pin Number Voltage Spec Remark (Main) 12 V 11.87 V 04-6232-008-010-000 8P 1.00MM FFC/FPC CN504 Connector,FFC/FPC/PIC STRAIGHT TOP SMD TP NON_LOCKING - KY- 5.13 V DISPLAY JIG OCERA CORPORATION 3.3 V 3.32 V 04-6495-626-000-846+ 26P 0.50MM FFC ANGLE CN506...

  • Page 47: Printed Circuit Board Diagrams

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

  • Page 48: Main P. C. Board Diagram

    2. MAIN P. C. BOARD DIAGRAM (TOP VIEW) (BOTTOM VIEW) 3-45 3-46...

  • Page 49: Front P. C. Board Diagram

    3. FRONT P. C. BOARD DIAGRAM (TOP VIEW) (BOTTOM VIEW) 3-47 3-48...
  • Page 50 SECTION 4 WIRELESS SUBWOOFER PART CONTENTS ONE POINT REPAIR GUIDE ..........................4-2 1. NO POWER PROBLEM (PVDD) ......................4-2 2. POWER ON ERROR ..........................4-3 3. POWER ON ERROR ..........................4-4 4. WIRELESS CONNECTION ........................4-5 WAVEFORMS OF MAJOR CHECK POINT ...................... 4-6 1.

  • Page 51: One Point Repair Guide

    ONE POINT REPAIR GUIDE 1. NO POWER PROBLEM (PVDD) No power problem occurs when you power on the unit 1-1. Solution If you check these points and find PVDD voltage is not checked, replace woofer SMPS board. 1-2. Service hint (Any picture / Remark) PVDD PVDD pin3, 4, 5, 6 at WCN601...

  • Page 52: Power On Error

    ONE POINT REPAIR GUIDE 2. POWER ON ERROR Fundamental power check points 2-1. 12 V 1) Check 12 V at WL604 nearby WL603 coil. 2) If 12 V is not checked at the point, then find PVDD at pin7 of WIC606. 3) 1), 2) is NG ...
  • Page 53 ONE POINT REPAIR GUIDE 3. POWER ON ERROR MAIN SoC IC supply voltage check points 3-1. 3.3 VA 1) Check 3.3 VA at WCA603 and WL627. 2) Check 3.3V_PWM at pin5 of WIC605. 3) Check 3.3 VA at pin7, 8 of WIC603. 4) Check 3.3V_PWM at WL615 nearby WIC601.

  • Page 54: Wireless Connection

    ONE POINT REPAIR GUIDE 4. WIRELESS CONNECTION Wireless connection malfunction 4-1. 3.3 VA 1) Check 3.3 VA at WL616. 4-2. Connection 1) Wireless module connection closely. 2) Implement Wireless Factory Reset.   MAIN SET : Soundbar vol MIN and push Mute key (sustain 3 ~ 5 sec). ...

  • Page 55: 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...

  • Page 56: Amp Voltage

    2. AMP VOLTAGE PVDD: 34.5 V FIG 2-1. Woofer PVDD FIG 2-2. Woofer 12 V...

  • Page 57: Pwm

    3. PWM FIG 3-1. Woofer PWM SW+ SIgnal FIG 3-2. Woofer PWM SW- SIgnal...

  • Page 58: Led

    4. LED FIG 4-1. Pairing Off Status  Red LED FIG 4-2. Pairing On Status  Yellow LED...
  • Page 59 4-10...

  • Page 60: Wiring Diagram

    WIRING DIAGRAM WOOFER AMP Wireless module PN901, DIP, 2P WOOFER WCN602, SMD, 24P, B to B (Power Cord) CN901, Harness Cable, (Wireless module) WCN601, DIP, 10P PAIRING KEY WCN604, DIP, 2P JK401, Harness Cable, WCN603, DIP, 2P WOOFER SMPS PCB (SWF) WCN605, DIP, 3P (LED CNT)

  • Page 61: 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...

  • Page 62: Circuit Diagrams

    DIFFER FROM THE ACTUAL CIRCUIT USED. THIS 2. Voltages are DC-measured with a digital voltmeter 1. WOOFER SMPS CIRCUIT DIAGRAM PERMISSION FROM THE LG CORPORATION. ALL WAY, IMPLEMENTATION OF THE LATEST SAFETY during Play mode. COMPONENTS SHOULD BE REPLACED ONLY WITH...

  • Page 63: Woofer Amp Circuit Diagram

    2. WOOFER AMP CIRCUIT DIAGRAM WF-AMP : WAVEFORM NUMBER EAX66304701 Rev1.2(10) 2015.11.17 4-17 4-18...

  • Page 64: Woofer Key Circuit Diagram

    3. WOOFER KEY CIRCUIT DIAGRAM WF-KEY EAX66305401 Rev1.2(9) 2015.11.17 4-19 4-20...

  • Page 65: Printed Circuit Board Diagrams

    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. 4-21 4-22...

  • Page 66: 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) 4-23 4-24...
  • Page 67 4-25 4-26...

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