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

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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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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 methodRGB Input RGB-PCAnalogD-SUB 15PIN HDMI1-DTV/DVI5.1. 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 S7LRAll rights reserved HalfEXPLODED VIEW EMEA INTERACTIVE GP4MSTAR2011 . 08 Copyright 2012 LG Electronics. Inc. All rights reservedOLED Step Up regulator 3 . 3V to 5VMAX 250mA THERMALFROM LIPS & POWER B/D PowerDET+1.5VDDR +3.3VNormalIC501 NTP-7500LCONTROL IR & LED 51Pin LVDS Connector 30Pin LVDS Connector For HD 60HzNormalFor FHD 60/120Hz MIRROR Pol - changeHDMI1 For CECHDMI2 SIDEHDMI0 . 3 3 u F RGB/SPDIF/PC/HP/USB USBDIODESS7LRDIVXMS10 IC1300 MX25L8006EM2I-12GIC1300-*1 W25Q80BVSSIGSI2176ATSC1INPUTH P4RGLOBALTUNERBLOCKSI2156DVB1INPUTH LGDT1001 IC1501PILG1001 A2 Full Scart/ Comp1 UART/I2C SWITCH EXTSPK AMPEXTSPKCONTROL/DEBUG EXTSPK OUTEXTERNALPOWER OUT 5V/12V REAL TIME CLOCKRTCCI Region Option name of this page CI SLOT because of Hong KongSMD GASKET Page 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 outputvoltages of Power Check variousNo Video BoardA. 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%Check color by input -External Input COMPONENT -RGB ※ Checkand replace Link CableConnect other external device and cable External device screen error-Color errorVertical/Horizontal bar, residual image, light spot Check color condition by input -External Input -Component RGBB. Power error Stand-By Red Operating whiteCheck Power LED Check Power On ‘”High”Check Power Off Starusinstart menu If Power Off mode is not displayed Check Power B/D voltagePOWEROFFABNORMAL1 POWEROFFCPUABNORMALC. Audio error Power BoardCheck user menu Speaker off Check audio B+In case of External Input signal error Check and fix external device 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 VersionE. Noise Identify nose typeF. Exterior defect A. 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 KeyAppendix 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 1. 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…)