LG Electronics 42LT640H-ZA service manual Appendix Exchange PSULED driver, No Light, Dim Light

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Appendix : Exchange PSU(LED driver)

No Light
No Light		Dim Light

Dim Light		Dim Light

No picture/Sound Ok

A - 3/5

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

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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 methodRGB-PC RGB InputAnalogD-SUB 15PIN HDMI1-DTV/DVI5. Video resolutions 2D 5.1. Component Input Y, CB/PB, CR/PR5.2. 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 & notice6.1. Download Procedure 6. CI+ Key Download methodCI+ Key Value S7LR BLOCK DIAGRAMAll rights reserved HalfEXPLODED VIEW GP4MSTAR EMEA INTERACTIVE2011 . 08 Copyright 2012 LG Electronics. Inc. All rights reservedOLED THERMAL Step Up regulator 3 . 3V to 5VMAX 250mAPowerDET FROM LIPS & POWER B/D+1.5VDDR +3.3VNormalNTP-7500L IC501CONTROL IR & LED 30Pin LVDS Connector For HD 60HzNormal 51Pin LVDS ConnectorFor FHD 60/120Hz MIRROR Pol - changeFor CEC HDMI1HDMI2 SIDEHDMI0 . 3 3 u F USBDIODES RGB/SPDIF/PC/HP/USBS7LRDIVXMS10 MX25L8006EM2I-12G IC1300IC1300-*1 W25Q80BVSSIGP4RGLOBALTUNERBLOCK SI2176ATSC1INPUTHSI2156DVB1INPUTH IC1501 LGDT1001PILG1001 A2 Full Scart/ Comp1 EXTSPK AMP UART/I2C SWITCHEXTSPKCONTROL/DEBUG EXTSPK OUTREAL TIME CLOCKRTC EXTERNALPOWER OUT 5V/12VOption name of this page CI SLOT because of Hong Kong CI RegionSMD GASKET Page 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 outputCheck various voltages of PowerNo Video BoardBy 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%※ Check Check color by input -External Input COMPONENT -RGBand replace Link CableExternal device screen error-Color error Connect other external device and cableVertical/Horizontal bar, residual image, light spot Check color condition by input -External Input -Component RGBStand-By Red Operating white B. Power errorCheck Power LED Check Power On ‘”High”If Power Off mode is not displayed Check Power B/D voltage Check Power Off Starusinstart menuPOWEROFFABNORMAL1 POWEROFFCPUABNORMALPower Board C. Audio errorCheck user menu Speaker off Check audio B+Check audio B+ Voltage 20V or In case of External Input signal error Check and fix external device1. 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. NoiseF. Exterior defect MENU -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 errorAppendix 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 2. 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