LG 42LB55 series Service Manual

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Owner's manual (480 pages)

Safety and reference (177 pages)

Owner's manual (84 pages)

Table Of Contents

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Summary of Contents for LG 42LB55 series

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 TV SERVICE MANUAL CHASSIS : LD43B/LD44B MODEL : 42LB55** 42LB55**-Z* 42LB552V 42LB552V-TB CAUTION BEFORE SERVICING THE CHASSIS, READ THE SAFETY PRECAUTIONS IN THIS MANUAL. P/NO : MFL68003704 (1312-REV00) Printed in Korea...
Page 2: Table Of Contents
SERVICING PRECAUTIONS ..............4 SPECIFICATION ..................6 ADJUSTMENT INSTRUCTION ............. 10 EXPLODED VIEW .................. 17 SCHEMATIC CIRCUIT DIAGRAM .............. - 2 - Copyright © LG Electronics. Inc. All rights reserved. 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. - 3 - Copyright © LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 5 1. Clip each fuse or resistor lead at top of the circuit board hollow stake. 2. Securely crimp the leads of replacement component around notch at stake top. - 5 - Copyright © LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 6: Specification
EUTELSAT-SESAT, ASTRA 1L/H/M/KR, ASTRA 3A/3B, BADR 4/6, ASTRA 2D, EUROBIRD 3, EUTELSAT-W7, HELLASSAT 2, EXPRESS AM1, TURKSAT 2A/3A, INTERSAT10 - 6 - Copyright © LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 7 LB62 : for DLNA Ethernet (1EA) DLNA(Wired, DMP only) T2 Model ( LB62, LB56, LB55 ) : for MHEG - 7 - Copyright © LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 8 HDTV 1080P 1920*1080 27.00 24.00 74.25 HDTV 1080P 1920*1080 26.97 23.976 74.176 HDTV 1080P 1920*1080 33.75 30.00 74.25 HDTV 1080P - 8 - Copyright © LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 9: Hdmi Input
Side by Side, Top & Bottom 6.5. 3D Input mode Side by Side Top & Bottom Single Frame Sequential Frame Packing - 9 - Copyright © LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 10: Adjustment Instruction
In this case, you have to channel recover. if all channel data is cleared, you didn’t have a DTV/ ATV test on production line. - 10 - Copyright © LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 11 12. EDID D/L ► 13. Sub B/C 14. Ext. Input Adjust <Caution> Never connect HDMI cable when EDID downloaded. - 11 - Copyright © LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 12 Medium 9,300 K Y=0.293 (±0.002) Y=0.299 LG TV 00 00 00 FC 00 4C 47 20 54 56 0A 20 20 20 20 20 20 20 (LG TV) X=0.313 (±0.002) X=0.320 Warm 6,500 K e. Checksum: Changeable by total EDID data.
Page 13 C0.(When R/G/B Gain are all C0, it is the FULL Dynamic Range of Module) - 13 - Copyright © LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 14 (1) Start 3D pattern inspection. (2) If IR emitter signal is correctly received to IR receiver, the lamp of IR tester turns on. - 14 - Copyright © LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 15 Data : Write data CS : CMD + LENGTH + ADH + ADL + Data_1 +...+ Data_n Delay : 20ms - 15 - Copyright © LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 16 ▪ Check the OK or NG (3) Play Test (F9) button and confirm OK Message. (4) Remove LAN cable. - 16 - Copyright © LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 17: Exploded View
X-RADIATION, Shock, Fire, or other Hazards. Do not modify the original design without permission of manufacturer. - 17 - Copyright © LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 19 2013.09.14 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR Power_PD2 THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 20 13/04/30 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR USB_S1 THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 21 FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR HDMI_R1_S1 THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 22 2013/05/15 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR SPDIF THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 23 2013/05/20 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR 1_DDR THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 24 2013/04/29 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR S_FLASH THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 25 2013.07.15 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR LVDS_EU THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 26 2013.04.29 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. PCMCI Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 27 FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 28 FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 29 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. SCART_ COMPONENT Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 30 2013.04.29 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR HEAD_PHONE_EU THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 31 2013.08.27 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR TUNER_EU THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 32 2013/04/30 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR RS232C_MSTAR_DEBUG_4P THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 33 FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR TP_EU THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 34 2013/09/03 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR IR_EYE_SENSOR THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 35 2013.08.27 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. MAIN1_EU Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 36 2013.08.27 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. MAIN2_EU Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 37 FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR AUDIO[TI] THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 38 2013.09.01 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR MHL_SW_AND THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 40 2013.09.14 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR Power_PD2 THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 41 13/04/30 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR USB_S1 THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 42 2013/05/15 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR SPDIF THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 43 2013/04/29 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR S_FLASH THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 44 2013.07.15 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR LVDS_EU THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 45 2013.04.29 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. PCMCI Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 46 FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR TUNER_EU_T/C THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 47 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. SCART_ COMPONENT Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 48 2013.04.29 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR HEAD_PHONE_EU THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 49 2013/04/30 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR RS232C_MSTAR_DEBUG_4P THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 50 FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR TP_EU THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 51 FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR HDMI_R2 THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 52 2013/09/03 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR IR_EYE_SENSOR THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 53 2013.08.27 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. MAIN1_EU Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 54 2013.08.27 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. MAIN2_EU Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 55 FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR AUDIO[TI] THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 56 2013.09.01 ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR MHL_SW_AND THE CRITICAL COMPONENTS IN THE SYMBOL MARK OF THE SCHEMETIC. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 59 F. Exterior error Exterior defect * First of all, Check whether there is SVC Bulletin in GCSC System for these model. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 60 A-3/5 Other : PSU Inverter/ Module Exchange Module itself (1) A-4/5 Exchange Module itself (2) A-5/5 Continue to the next page Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 61 Always check & record S/W Version and White Replace Main Board Re-enter White Balance value Balance value before replacing the Main Board Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 62 No Video/ Normal voltages of Power replace No audio Voltage Board ( 3.5V,12V, 24V) MAIN B/D Replace Power Board and repair parts Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 63 2. Install Booster Normal Replace Contact with signal distributor S/W Upgrade Picture or broadcaster (Cable or Air) Main B/D Normal Picture Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 64 Contact with signal Change satellite setting S/W Upgrade distributor (match with installed ANT) or broadcaster (Cable or Air) Normal Normal Picture Picture Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 65 Normal cable error Request repair for external device/cable External Check external HDMI device/Cable device and Replace Main B/D error Normal cable Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 66 (Check normal operation of External Input, HDMI Screen Replace error Component, HDMI by normal Main B/D connecting Jig, pattern Generator ,Set-top Box etc. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 67 Measure voltage of each output of Power B/D Normal ☞A12 ※ Normal Normal Check ST-BY 3.5V Replace Main B/D Voltage Voltage Replace Power B/D Replace Power B/D Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 68 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 © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 69 Speaker off Board Cancel OFF Replace Power Board and repair parts Check Disconn Speaker Replace MAIN Board ection disconnection Replace Speaker Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 70 Request repair to external Audio cable/ANT provider (In case of External Input Check and fix external device signal error) Check and fix external device Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 71 (Power B/D don’t have problem) If R/C operate, Normal Explain the customer Operating cause is interference from light in room. Replace R/C Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 72 - S/W Version Fix in accordance Check and fix HDMI, Optical Replace Main B/D with technical external device/cable Recognition error information Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 73 “Part related to nose” in the Owner’s Manual. as shown in the solution manual (For models without any fix information, provide the description) Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 74 Zoom part with Module Replace module exterior damage damage Cabinet Replace cabinet damage Remote Controller Replace remote controller damage Stand Replace stand damage Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 75 Voltage and speaker checking method in audio/discontinuation case of audio error D. Function error_ No response in Remote controller operation checking method remote controller, key error Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 76 Check Back Light On with naked eye date <ALL MODELS> Power On -> disjoint back case -> check lighting at 2 points. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 77 1. Measure DC 24V applying to inverter PCB from Power Board. 2. Output 24V from Power Board -> supply to inverter PCB. Check Pin contacting statement and connection statement. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 78 3. After recording the R, G, B (GAIN, Cut) value of Color Temp (Cool/Medium/Warm), re- enter the value after replacing the MAIN BOARD. enter the value after replacing the MAIN BOARD. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 79 Check DC 3.5V, 12V, 24V 18 Pin (Power Board ↔ Main Board) SMAW200-H18S5 Power on DRV ON 3.5V PDIM#1 3.5V 3.5V PDIM#2 Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 80 MENU => Press red key Remote controller=>signal test => Select channel When the signal is strong, use the attenuator (-10dB, -15dB, -20dB etc.) Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 81 LCD-TV Version checking method Content date 1. Checking method for remote controller for adjustment Version Press the IN-START with the remote controller for adjustment Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 82 LCD TV connection diagram (1) date <ALL MODELS> As the part connecting to the external input, check the screen condition by signal Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 83 Check and replace Link Cable(LVDS) and contact condition date <ALL MODELS> 1. Check and replace LVDS Cable 2. Check LVDS connection condition Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 84 Checking item : 1. Defective pixel 2. Residual image 3. MODULE error (ADD-BAR,SCAN BAR..) 4.Video error (Classification of MODULE or Main-B/D!) Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 85 Solder defect, CNT Broken Solder defect, CNT Broken T-Con Defect, CNT Broken Abnormal Power Section Solder defect, Short/Crack Solder defect, Short/Crack Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 86 Abnormal Power Section Abnormal Power Section Solder defect, Short/Crack Abnormal Display Fuse Open, Abnormal power section Solder defect, Short/Crack Noise GRADATION GRADATION Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 87 Appendix : Exchange PSU(LED driver) No Light Dim Light Dim Light Dim Light No picture/Sound Ok Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 88 Panel Mura, Light leakage Press damage Crosstalk Press damage Crosstalk Un-repairable Cases In this case please exchange the module. Press damage Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 89 Gate TAB IC Defect Un-repairable Cases In this case please exchange the module. Horizontal Block Gate TAB IC Defect Gate TAB IC Defect Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 90 Content Check front display LED date ST-BY condition: Red Front LED control : Menu  Option  Standby Light  On/Off Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 91 Check DC 3.5V, 12V, 24V 18 Pin (Power Board ↔ Main Board) SMAW200-H18S5 Power on DRV ON 3.5V PDIM#1 3.5V 3.5V PDIM#2 Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 92 Check “power on(Pin 1)” pin is high(about 3.3V) 18 Pin (Power Board ↔ Main Board) SMAW200-H18S5 Power on DRV ON 3.5V PDIM#1 3.5V 3.5V PDIM#2 Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 93 Checking order 1. Press the IN-START button of the remote controller for adjustment 2. Check the entry into adjustment item 3. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 94 1. Press the MENU button on the remote controller 2. Select the AUDIO function of the Menu 3. Select TV Speaker Check Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only Only for training and service purposes...
Page 95 3. Connect the tester RX1 to the speaker terminal and if you hear the Chik Chik sound when you touch the GND and output terminal, the speaker is normal. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only...
Page 96 When checking the Pre-Amp when the power is in ON condition, it is normal when the Analog Tester needle moves slowly, and defective when it does not move at all. Copyright © 2014 LG Electronics. Inc. All rights reserved. LGE Internal Use Only...

This manual is also suitable for:

42lb552v 50lb56 series 32lb55**-z series 32lb552u 32lb55 series 32lb552u-tb

LG 42LB55 series Service Manual

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Summary of Contents for LG 42LB55 series

Page 2: Table Of Contents

Page 3: Safety Precautions

Page 4: Servicing Precautions

Page 6: Specification

Page 9: Hdmi Input

Page 10: Adjustment Instruction

Page 17: Exploded View

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Table of Contents