LG 55LH90QD Service Manual
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LG 55LH90QD Service Manual

LG 55LH90QD Service Manual

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LED LCD TV
SERVICE MANUAL
CHASSIS : LT91C
MODEL : 55LH90QD
CAUTION
BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
P/NO : MFL62149713(0907-REV00)
North/Latin America
Europe/Africa
Asia/Oceania
55LH90QD-DC
Internal Use Only
http://aic.lgservice.com
http://eic.lgservice.com
http://biz.lgservice.com
Printed in Korea

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  • Page 1 Internal Use Only North/Latin America http://aic.lgservice.com Europe/Africa http://eic.lgservice.com Asia/Oceania http://biz.lgservice.com LED LCD TV SERVICE MANUAL CHASSIS : LT91C MODEL : 55LH90QD 55LH90QD-DC CAUTION BEFORE SERVICING THE CHASSIS, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. P/NO : MFL62149713(0907-REV00) Printed in Korea...

  • Page 2: Table Of Contents

    CONTENTS ....................2 PRODUCT SAFETY ..................3 SPECIFICATION ..................6 ADJUSTMENT INSTRUCTION ...............12 BLOCK DIAGRAM...................18 EXPLODED VIEW .................. 19 SVC. SHEET ....................Copyright ©2009 LG Electronics. Inc. All right reserved. - 2 - LGE Internal Use Only Only for training and service purposes...

  • Page 3: Safety Precautions

    An other abnormality exists that must be corrected before the receiver is returned to the customer. Copyright ©2009 LG Electronics. Inc. All right reserved. - 3 - LGE Internal Use Only Only for training and service purposes...

  • Page 4: Servicing Precautions

    Alternatively, obtain and wear a commercially available discharging wrist strap device, which should be removed to prevent potential shock reasons prior to applying power to the Copyright ©2009 LG Electronics. Inc. All right reserved. - 4 - LGE Internal Use Only...
  • Page 5 CAUTION: Maintain original spacing between the replaced component and adjacent components and the circuit board to prevent excessive component temperatures. Copyright ©2009 LG Electronics. Inc. All right reserved. - 5 - LGE Internal Use Only Only for training and service purposes...

  • Page 6: Application Range

    With inverter Pixel Pitch 0.63000 (H) x 0.63000 (V) Back Light Display Colors 1.06Billion (10 bit) Coating 3H, Semi-glare Copyright ©2009 LG Electronics. Inc. All right reserved. - 6 - LGE Internal Use Only Only for training and service purposes...
  • Page 7 Case 1 : P1:10,000: 1 , P2 :1000:1 in 25% window over 100 Blocks Case 2 : P1:10,000: 1 , P2 :1000:1 in 16% window under 100 Blocks Copyright ©2009 LG Electronics. Inc. All right reserved. - 7 - LGE Internal Use Only...
  • Page 8 Dynamic CR 40000:1 -> Measure the black luminance after 30 seconds. Item Remark Dynamic CR HDMI 720p Full Black pattern 1,800,000 2,000,00 (Only HDMI mode) Copyright ©2009 LG Electronics. Inc. All right reserved. - 8 - LGE Internal Use Only Only for training and service purposes...
  • Page 9 Item Unit Remarks Video Input Level Audio Input Level Vrms Component Video Input Level (Y,C R/G/B Video Input Level, Copyright ©2009 LG Electronics. Inc. All right reserved. - 9 - LGE Internal Use Only Only for training and service purposes...

  • Page 10: Component Video Input

    29.976 / 30.00 74.25 HDTV 1080P 1920*1080 56.250 148.5 HDTV 1080P 1920*1080 67.43 / 67.5 59.94 / 60 148.35/148.50 HDTV 1080P Copyright ©2009 LG Electronics. Inc. All right reserved. - 10 - LGE Internal Use Only Only for training and service purposes...

  • Page 11: Mechanical Specification

    (W/O Packing) W/O Neck Dimension Commercial (With Packing) Weight(W/O Packing) With Neck Weight(With Packing) Appearance Refer to Standard of LG(56)G4-9002 Copyright ©2009 LG Electronics. Inc. All right reserved. - 11 - LGE Internal Use Only Only for training and service purposes...

  • Page 12: Adjustment Instruction

    If “Error” is displayed, Check connection between computer, jig, and set.. (3) Click “Read” tab, and then load download file (XXXX.bin) by clicking “Read”. Copyright ©2009 LG Electronics. Inc. All right reserved. - 12 - LGE Internal Use Only Only for training and service purposes...

  • Page 13: Function Check

    45891 3144 55462 20736 * Display and Sound check is executed by remote control. 4. Completed selecting Tool option. Copyright ©2009 LG Electronics. Inc. All right reserved. - 13 - LGE Internal Use Only Only for training and service purposes...

  • Page 14: Adjustment Preparation

    - LEN: Number of Data Byte to be send - CMD: Command - VAL: FOS Data - CS: Checksum of sent Data - A: Acknowledge Copyright ©2009 LG Electronics. Inc. All right reserved. - 14 - LGE Internal Use Only Only for training and service purposes...
  • Page 15 0 When transfer the ‘Mode In’, ‘Mode In’ Carry the command. Download 00 10 Automatically Download (The use of a internal pattern) Copyright ©2009 LG Electronics. Inc. All right reserved. - 15 - LGE Internal Use Only Only for training and service purposes...
  • Page 16 MODEL NAME(HEX) 00 00 00 FC 00 4C 47 20 54 56 0A 20 20 20 20 20 20 20 Checksum: Changeable by total EDID data. Copyright ©2009 LG Electronics. Inc. All right reserved. - 16 - LGE Internal Use Only...
  • Page 17 • checking the function of Dimming refer to the Picture at below • Push the button “Exit” Patter 7 (combination) Copyright ©2009 LG Electronics. Inc. All right reserved. - 17 - LGE Internal Use Only Only for training and service purposes...

  • Page 18: Block Diagram

    BLOCK DIAGRAM Copyright ©2009 LG Electronics. Inc. All right reserved. - 18 - LGE Internal Use Only Only for training and service purposes...

  • Page 19: Exploded View

    X-RADIATION, Shock, Fire, or other Hazards. Do not modify the original design without permission of manufacturer. Copyright LG Electronics. Inc. All right reserved. - 19 - LGE Internal Use Only Only for training and service purposes...
  • Page 20 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 21 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 22 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 23 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 24 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 25 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 26 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 27 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 28 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 29 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 30 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 31 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 33 Remote control & Local switch checking D. Function error External device recognition error E. Noise Circuit noise, mechanical noise F. Exterior error Exterior defect Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 34 Always check & record S/W Version and White Replace Main Board Re-enter White Balance value Balance value before replacing the Main Board Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 35 Power No Video/ replace voltage? No audio Board ( 5V,12V,20V MAIN B/D or 24V…) Replace Power Board and repair parts Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 36 Normal Contact with signal distributor Picture? or broadcaster (Cable or Air) Check Normal Tuner soldering Picture? Close Replace Main B/D Close Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 37 Request repair for external device/cable RGB/ Check external External device device and Replace Main B/D HDMI/DVI /Cable error cable normal Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 38 (Check normal operation of Main B/D normal? External Input, Component, HDMI/ RGB and HDMI/DVI by connecting Jig, pattern Generator ,Set-top Box etc. Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 39 If mechanical power switch off → Doesn’t turn on by remote control → Doesn’t appear LED light Please refer to the A21 Page Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 40 Power off by unknown status except listed case "POWEROFF_ABNORMAL1" Power off by abnormal status except CPU trouble Abnormal "POWEROFF_CPUABNORMAL" Power off by CPU Abnormal Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 41 Power Board Cancel OFF and describe Replace Power Board and repair parts Check Disconnection Replace MAIN Board Speaker disconnection Replace Speaker Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 42 External Input Connect and check Normal signal error) other external audio? Check and fix device external device Check and fix external device Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 43 Signal? Operation Output signal Connector solder (Key PCB + tool ) Close Close Repair/Replace Move Local switch B/D Power problem Section Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 44 - S/W Version RGB,HDMI/ Check and fix DVI, Optical Replace Main B/D Fix in external device/cable Recognition error accordance with technical information Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 45 ※ Describe the basis of the description (For models without any fix information, in “Part related to nose” in the Owner’s provide the description) Manual. Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 46 Zoom part with Replace module exterior damage damage Cabinet Replace cabinet damage Remote controller Replace remote controller damage Stand Replace stand dent Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 47 AV / Component / RGB, HDMI-PC/ HDMI-DTV No Audio (SPDIF) USB / Remocon Problem USB no connect / Remocon 36/37 Intelligent Sensor Intelligent Sensor Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 48 Replace MAIN B’D IC102 Replace MAIN B’D IC103 Replace MAIN B’D Replace MAIN B’D IC100 NAND FLASH Serial Flash IC300, IC301 DDR2 Memory Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 49 MAIN B’D L810 = 12V ? Replace MAIN B’D Q805 Check LVDS Cable Replace Main Board OK ? Replace LVDS Cable Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 50 Replace MAIN B’D IC1103 MAIN B’D L1113 = 1.8V ? Replace MAIN B’D IC1105 MAIN B’D X1101 Clock ? Replace MAIN B’D X1101 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 51 Replace MAIN B’D IC1103 MAIN B’D L1113 = 1.8V ? Replace MAIN B’D IC1105 MAIN B’D X1101 Clock ? Replace MAIN B’D X1101 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 52 Replace MAIN B’D JK402 Video Signal ? Check MAIN B’D C217 Replace Video Signal ? MAIN B’D C217 Replace MAIN B’D IC 100 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 53 Replace MAIN B’D JK404 Video Signal ? Check MAIN B’D C211 Replace Video Signal ? MAIN B’D C211 Replace MAIN B’D IC 100 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 54 C201 (Pb) Replace C202 (Pr) MAIN B’D C200 or C203 or C201 or C202 Video Signal ? Replace MAIN B’D IC 100 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 55 C215 (Pb) Replace C216 (Pr) MAIN B’D C214 or C209 or C215 or C216 Video Signal ? Replace MAIN B’D IC 100 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 56 Check MAIN B’D C207 (Video) Replace R2030 (HSYNC) MAIN B’D C207 or R2030 or R2031 R2031 (VSYNC) Replace MAIN B’D IC 100 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 57 Check MAIN B’D C2016 (RED) C2017 (GREEN) Replace C2018 (BLUE) MAIN B’D C2016 or C2017 or C2018 Video Signal ? Replace MAIN B’D IC 100 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 58 Check the ADJUST MENU (Refer to Adjustment Spec) EDID OK ? Replace MAIN B’D IC601 (HDCP KEY) Replace MAIN B’D IC 100 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 59 MAIN B’D JACK Check JK600 -> HDMI1 JK601 -> HDMI2 JK602 -> HDMI3 JK603 -> HDMI4 Replace MAIN B’D IC 100 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 60 L705 Pin #1 Check P700 Cable Replace MAIN B’D IC701 L704 Pin #2 PWM Signal ? Replace MAIN B’D IC 701 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 61 2009. 2 . 1 Digital TV No Audio Problem LCD TV Symptom 14/25 Revision Digital TV Video OK ? Replace MAIN B’D IC 100 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 62 Analog TV Video OK ? Check MAIN B’D Replace MAIN B’D IC100 R2046 Signal (SIF) MAIN B’D Replace MAIN B’D IC1102 L1101 Signal (SIF) Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 63 Replace MAIN B’D JK402 MAIN B’D C2011 (Right Sound) Replace MAIN B’D IC 100 C2012 (Left Sound) signal ? Check MAIN B’D C229, C230 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 64 Replace MAIN B’D JK402 MAIN B’D C2008 (Right Sound) Replace MAIN B’D IC 100 C2009 (Left Sound) signal ? Check MAIN B’D C2008, C2009 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 65 Replace MAIN B’D JK402 MAIN B’D C229 (Right Sound) Replace MAIN B’D IC 100 C230 (Left Sound) signal ? Check MAIN B’D C229, C230 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 66 Replace MAIN B’D JK402 MAIN B’D C2013 (Right Sound) Replace MAIN B’D IC 100 C2014 (Left Sound) signal ? Check MAIN B’D C2013, C2014 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 67 Replace MAIN B’D JK401 MAIN B’D C2015 (Right Sound) Replace MAIN B’D IC 100 C2016 (Left Sound) signal ? Check MAIN B’D C2015, C2016 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 68 Check the ADJUST MENU Download EDID EDID OK ? (Refer to Adjustment Spec) Check the HDMI Cable Replace MAIN B’D IC100 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 69 Check the SPDIF Cable Check MAIN B’D JK403 Replace MAIN B’D JK403 Check MAIN B’D R2305 PWM Signal ? Replace MAIN B’D IC 100 Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 70 JK406 Pin #1 5V ? Check MAIN B’D Replace MAIN B’D IC808 R826 5V ? Check MAIN B’D Replace POWER B’D R848 12V ? Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 71 24/25 Revision Check MAIN B’D P5001 Replace it Wafer & Connector Check IR B’D P1 Wafer Replace IR B’D & Connector Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...
  • Page 72 25/25 Revision Check MAIN B’D P5001 Replace it Wafer & Connector Check IR B’D P1 Wafer Replace IR B’D & Connector Copyright ⓒ 2009 LG Electronics. Inc. All right reserved. Only for training and service purposes LGE Internal Use Only...

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