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LG Electronics 42LT640H-ZA Checking method, C. Audio errorNo audio/Normal video, Lcd Tv

Models: 42LT640H-ZA

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Standard Repair Process Detail Technical Manual

LCD TV

Error	C. Audio error_No audio/Normal video	Established
symptom
		date
Content	Checking method in menu when there is no audio	Revised	A24
		date

Checking method

1.Press the MENU button on the remote controller

2.Select the AUDIO function of the Menu

3.Select TV Speaker from Off to On

A24

Copyright © 2012 LG Electronics. Inc. All rights reserved.	LGE Internal Use Only
Only for training and service purposes

Page 61

Image 61

LG Electronics 42LT640H-ZA Checking method, C. Audio errorNo audio/Normal video, Select the AUDIO function of the Menu

Contents

http//aic.lgservice.com READ THE SAFETY PRECAUTIONS IN THIS MANUALhttp//eic.lgservice.com http//biz.lgservice.comSAFETY PRECAUTIONS CONTENTSSERVICING PRECAUTIONS SPECIFICATIONIMPORTANT SAFETY NOTICE SAFETY PRECAUTIONSElectrostatically Sensitive ES Devices SERVICING PRECAUTIONSReplacement IC Remove/ReplacementSmall-Signal Discrete Transistor Removal/Replacement Removal4. Model General Specification SPECIFICATION1. Application range 3. Test methodOnly for training and service purposes SpecificationRemarks RGB Input5.1. Component Input Y, CB/PB, CR/PR 5. Video resolutions 2D5.2. RGB Input PC PCDVI 5.3. HDMI InputPC/DTVBoot file Download ADJUSTMENT INSTRUCTIONAfter downloading, have to adjust Tool Option again 1. Application Range4.1. Adjustment Preparation 4. Total Assembly line process3.1. ADC Process 3.2. Function Check4.2. DDC EDID Write RGB 128Byte 4.4. EDID data4.3 DDC EDID Write HDMI 256Byte Manual W/B process using adjust Remote control4.6. HI-POT Test 4.5. Outgoing condition Configuration4.6.1. HI-POT auto-check preparation 4.6.2. HI-POT auto-check5. Model name & Serial number D/L 5.1. Signal Table5.2. Comand Set 5.3. Method & notice6. CI+ Key Download method 6.1. Download ProcedureCI+ Key Value S7LR BLOCK DIAGRAMCopyright All rights reservedEXPLODED VIEW EMEA INTERACTIVE Only for training and service purposesGP4MSTAR 2011 . 08OLED Copyright 2012 LG Electronics. Inc. All rights reserved Only for training and service purposesLGE Internal Use Only Step Up regulator 3 . 3V to 5VMAX 250mAPowerDET FROM LIPS & POWER B/D+1.5VDDR +3.3VNormalNTP-7500L IC501Only for training and service purposes CONTROL IR & LEDCopyright 2012 LG Electronics. Inc. All rights reserved LGE Internal Use Only51Pin LVDS Connector Only for training and service purposes30Pin LVDS Connector For HD 60HzNormal Copyright 2012 LG Electronics. Inc. All rights reservedHDMI1 Only for training and service purposesFor CEC HDMI2Copyright 2012 LG Electronics. Inc. All rights reserved Only for training and service purposesLGE Internal Use Only 0 . 3 3 u FUSBDIODES RGB/SPDIF/PC/HP/USBOnly for training and service purposes Copyright 2012 LG Electronics. Inc. All rights reservedS7LRDIVXMS10 Only for training and service purposesEMEA INTERACTIVE Copyright 2012 LG Electronics. Inc. All rights reservedCopyright 2012 LG Electronics. Inc. All rights reserved Only for training and service purposesLGE Internal Use Only IC1300P4RGLOBALTUNERBLOCK Only for training and service purposesSI2176ATSC1INPUTH SI2156DVB1INPUTHLGDT1001 IC1501Only for training and service purposes PILG1001 A2Only for training and service purposes Full Scart/ Comp1Copyright 2012 LG Electronics. Inc. All rights reserved LGE Internal Use OnlyEXTSPK AMP UART/I2C SWITCHEXTSPKCONTROL/DEBUG EXTSPK OUTOnly for training and service purposes EXTERNALPOWER OUT 5V/12VCopyright 2012 LG Electronics. Inc. All rights reserved LGE Internal Use OnlyOption name of this page CI SLOT because of Hong Kong CI RegionOnly for training and service purposes Copyright 2012 LG Electronics. Inc. All rights reservedOnly for training and service purposes SMD GASKETCopyright 2012 LG Electronics. Inc. All rights reserved LGE Internal Use OnlyPage 1. Trouble Shooting Contents of LCD TV Standard Repair ProcessMain B/D↔ Power B/D, LVDS Cable,Speaker Cable,IR B/D Cable A. Video errorLCD TV A2 Check Power Board 24V,12V,3.5V outputvoltages of Power A. Video errorOnly for training and service purposes LCD TVBy using Digital signal level meter A. Picture ProblemBy using Diagnostics menu on OSD Menu→Setup→Manual Tuning Signal strength Normal over 30% Signal Quality Normal over 30%LCD TV A. Video errorCheck color by input -External Input COMPONENT -RGB ※ CheckExternal device screen error-Color error Connect other external device and cableA. Video error Vertical/Horizontal bar, residual image, light spotStand-By Red Operating white B. Power errorCheck Power LED Check Power On ‘”High”Check Power Off Starusinstart menu B. Power errorIf Power Off mode is not displayed Check Power B/D voltage POWEROFFABNORMAL1Power Board C. Audio errorLCD TV Check user menu Speaker offIn case of External Input signal error Check and fix external device C. Audio errorLCD TV Check audio B+ Voltage 20V or1. Remote controlR/C operating error D. General Function ProblemCheck & Repair Cable connection Connector solder Output signalCheck input signal D. Function errorY Check technical Signal information input? - Fix information S/W VersionIdentify nose type E. NoiseLCD TV LCD TV F. Exterior defectMENU -Æ red keycustomer support -Æ signal test -Æ select channel A. Video errorVideo error, video lag/stopWhen the signal is strong, use the attenuator -10dB, -15dB, -20dB etc Standard Repair Process Detail Technical ManualPress the IN-START with the remote controller for adjustment 1. Checking method for remote controller for adjustmentALL MODELS VersionYou can view 6 types of patterns using the ADJ Key A. Video errorColor errorOnly for training and service purposes Standard Repair Process Detail Technical ManualAppendix Exchange T-Con Board Appendix Exchange T-Con Board No Light Appendix Exchange PSULED driverDim Light No picture/Sound Ok A - 3/5Un-repairable Cases In this case please exchange the module Appendix Exchange the ModulePanel Mura, Light leakage Press damageUn-repairable Cases In this case please exchange the module Appendix Exchange the Module2. Check the entry into adjustment item 1. Press the IN-START button of the remote controller for adjustmentB. Power error Off when on, off whiling viewing Entry method1. Press the MENU button on the remote controller C. Audio errorNo audio/Normal videoChecking method 2. Select the AUDIO function of the Menu

C. Audio error_No audio/Normal video

Checking method

1.Press the MENU button on the remote controller

2.Select the AUDIO function of the Menu

3.Select TV Speaker from Off to On