Manuals / LG Electronics / TV and Video / Flat Panel Television

LG Electronics 42LT640H-ZA A. Video error, Lcd Tv, Check various, voltages of Power, No Video

Models: 42LT640H-ZA

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Standard Repair Process

	Error	A. Video error	Established
LCD TV	Error	A. Video error	date
LCD TV	symptom	No video/ No audio	Revised date	2/13
		No video/ No audio	Revised date	2/13

☞A4

		Check various
		voltages of Power
No Video/		voltages of Power
No Video/		Board
No audio		Board
No audio		( 3.5V,12V,20V or
		( 3.5V,12V,20V or
		24V…)

Normal Y voltage?

Replace Power Board and repair parts

Check and replace

MAIN B/D

End

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

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Image 40

LG Electronics 42LT640H-ZA A. Video error, Lcd Tv, Check various, voltages of Power, No Video, Board, No audio, 24V…

Contents

READ THE SAFETY PRECAUTIONS IN THIS MANUAL http//aic.lgservice.comhttp//eic.lgservice.com http//biz.lgservice.comCONTENTS SAFETY PRECAUTIONSSERVICING PRECAUTIONS SPECIFICATIONSAFETY PRECAUTIONS IMPORTANT SAFETY NOTICESERVICING PRECAUTIONS Electrostatically Sensitive ES DevicesIC Remove/Replacement ReplacementSmall-Signal Discrete Transistor Removal/Replacement RemovalSPECIFICATION 4. Model General Specification1. Application range 3. Test methodSpecification Only for training and service purposesRemarks RGB Input5.1. Component Input Y, CB/PB, CR/PR 5. Video resolutions 2D5.2. RGB Input PC 5.3. HDMI InputPC/DTV PCDVIADJUSTMENT INSTRUCTION Boot file DownloadAfter downloading, have to adjust Tool Option again 1. Application Range4. Total Assembly line process 4.1. Adjustment Preparation3.1. ADC Process 3.2. Function Check4.4. EDID data 4.2. DDC EDID Write RGB 128Byte4.3 DDC EDID Write HDMI 256Byte Manual W/B process using adjust Remote control4.5. Outgoing condition Configuration 4.6. HI-POT Test4.6.1. HI-POT auto-check preparation 4.6.2. HI-POT auto-check5.1. Signal Table 5. Model name & Serial number D/L5.2. Comand Set 5.3. Method & notice6. CI+ Key Download method 6.1. Download ProcedureCI+ Key Value BLOCK DIAGRAM S7LRCopyright All rights reservedEXPLODED VIEW Only for training and service purposes EMEA INTERACTIVEGP4MSTAR 2011 . 08OLED Only for training and service purposes Copyright 2012 LG Electronics. Inc. All rights reservedLGE Internal Use Only Step Up regulator 3 . 3V to 5VMAX 250mAFROM LIPS & POWER B/D PowerDET+1.5VDDR +3.3VNormalIC501 NTP-7500LCONTROL IR & LED Only for training and service purposesCopyright 2012 LG Electronics. Inc. All rights reserved LGE Internal Use OnlyOnly for training and service purposes 51Pin LVDS Connector30Pin LVDS Connector For HD 60HzNormal Copyright 2012 LG Electronics. Inc. All rights reservedOnly for training and service purposes HDMI1For CEC HDMI2Only for training and service purposes Copyright 2012 LG Electronics. Inc. All rights reservedLGE Internal Use Only 0 . 3 3 u FRGB/SPDIF/PC/HP/USB USBDIODESOnly for training and service purposes Copyright 2012 LG Electronics. Inc. All rights reservedOnly for training and service purposes S7LRDIVXMS10EMEA INTERACTIVE Copyright 2012 LG Electronics. Inc. All rights reservedOnly for training and service purposes Copyright 2012 LG Electronics. Inc. All rights reservedLGE Internal Use Only IC1300Only for training and service purposes P4RGLOBALTUNERBLOCKSI2176ATSC1INPUTH SI2156DVB1INPUTHIC1501 LGDT1001Only for training and service purposes PILG1001 A2Full Scart/ Comp1 Only for training and service purposesCopyright 2012 LG Electronics. Inc. All rights reserved LGE Internal Use OnlyUART/I2C SWITCH EXTSPK AMPEXTSPKCONTROL/DEBUG EXTSPK OUTEXTERNALPOWER OUT 5V/12V Only for training and service purposesCopyright 2012 LG Electronics. Inc. All rights reserved LGE Internal Use OnlyCI Region Option name of this page CI SLOT because of Hong KongOnly for training and service purposes Copyright 2012 LG Electronics. Inc. All rights reservedSMD GASKET Only for training and service purposesCopyright 2012 LG Electronics. Inc. All rights reserved LGE Internal Use OnlyPage Contents of LCD TV Standard Repair Process 1. Trouble ShootingA. Video error Main B/D↔ Power B/D, LVDS Cable,Speaker Cable,IR B/D CableLCD TV A2 Check Power Board 24V,12V,3.5V outputA. Video error voltages of PowerOnly for training and service purposes LCD TVA. Picture Problem By using Digital signal level meterBy using Diagnostics menu on OSD Menu→Setup→Manual Tuning Signal strength Normal over 30% Signal Quality Normal over 30%A. Video error LCD TVCheck color by input -External Input COMPONENT -RGB ※ CheckConnect other external device and cable External device screen error-Color errorA. Video error Vertical/Horizontal bar, residual image, light spotB. Power error Stand-By Red Operating whiteCheck Power LED Check Power On ‘”High”B. Power error Check Power Off Starusinstart menuIf Power Off mode is not displayed Check Power B/D voltage POWEROFFABNORMAL1C. Audio error Power BoardLCD TV Check user menu Speaker offC. Audio error In case of External Input signal error Check and fix external deviceLCD TV Check audio B+ Voltage 20V orD. General Function Problem 1. Remote controlR/C operating errorCheck & Repair Cable connection Connector solder Output signalD. Function error Check input signalY Check technical Signal information input? - Fix information S/W VersionIdentify nose type E. NoiseLCD TV F. Exterior defect LCD TVA. Video errorVideo error, video lag/stop MENU -Æ red keycustomer support -Æ signal test -Æ select channelWhen the signal is strong, use the attenuator -10dB, -15dB, -20dB etc Standard Repair Process Detail Technical Manual1. Checking method for remote controller for adjustment Press the IN-START with the remote controller for adjustmentALL MODELS VersionA. Video errorColor error You can view 6 types of patterns using the ADJ KeyOnly for training and service purposes Standard Repair Process Detail Technical ManualAppendix Exchange T-Con Board Appendix Exchange T-Con Board Appendix Exchange PSULED driver No LightDim Light No picture/Sound Ok A - 3/5Appendix Exchange the Module Un-repairable Cases In this case please exchange the modulePanel Mura, Light leakage Press damageAppendix Exchange the Module Un-repairable Cases In this case please exchange the module1. Press the IN-START button of the remote controller for adjustment 2. Check the entry into adjustment itemB. Power error Off when on, off whiling viewing Entry methodC. Audio errorNo audio/Normal video 1. Press the MENU button on the remote controllerChecking method 2. Select the AUDIO function of the Menu

Check various

voltages of Power

No Video/

Board

No audio

( 3.5V,12V,20V or

24V…)