Checking method, Lcd Tv, All Models | LG Electronics 42LT640H-ZA

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

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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.com SAFETY PRECAUTIONS CONTENTSSERVICING PRECAUTIONS SPECIFICATION IMPORTANT SAFETY NOTICE SAFETY PRECAUTIONS Electrostatically Sensitive ES Devices SERVICING PRECAUTIONS Replacement IC Remove/ReplacementSmall-Signal Discrete Transistor Removal/Replacement Removal 4. Model General Specification SPECIFICATION1. Application range 3. Test method RGB-PC RGB InputAnalogD-SUB 15PIN HDMI1-DTV/DVI 5.1. Component Input Y, CB/PB, CR/PR 5. Video resolutions 2D5.2. RGB Input PC PCDVI 5.3. HDMI InputPC/DTV Boot file Download ADJUSTMENT INSTRUCTIONAfter downloading, have to adjust Tool Option again 1. Application Range 4.1. Adjustment Preparation 4. Total Assembly line process3.1. ADC Process 3.2. Function Check 4.2. DDC EDID Write RGB 128Byte 4.4. EDID data4.3 DDC EDID Write HDMI 256Byte Manual W/B process using adjust Remote control 4.6. HI-POT Test 4.5. Outgoing condition Configuration4.6.1. HI-POT auto-check preparation 4.6.2. HI-POT auto-check 5. Model name & Serial number D/L 5.1. Signal Table5.2. Comand Set 5.3. Method & notice 6. CI+ Key Download method 6.1. Download ProcedureCI+ Key Value S7LR BLOCK DIAGRAMAll rights reserved Half EXPLODED VIEW GP4MSTAR EMEA INTERACTIVE2011 . 08 Copyright 2012 LG Electronics. Inc. All rights reserved OLED THERMAL Step Up regulator 3 . 3V to 5VMAX 250mA PowerDET FROM LIPS & POWER B/D+1.5VDDR +3.3VNormal NTP-7500L IC501 CONTROL IR & LED 30Pin LVDS Connector For HD 60HzNormal 51Pin LVDS ConnectorFor FHD 60/120Hz MIRROR Pol - change For CEC HDMI1HDMI2 SIDEHDMI 0 . 3 3 u F USBDIODES RGB/SPDIF/PC/HP/USB S7LRDIVXMS10 MX25L8006EM2I-12G IC1300IC1300-*1 W25Q80BVSSIG SI2176ATSC1INPUTH P4RGLOBALTUNERBLOCKSI2156DVB1INPUTH LGDT1001 IC1501PILG1001 A2 Full Scart/ Comp1 EXTSPK AMP UART/I2C SWITCHEXTSPKCONTROL/DEBUG EXTSPK OUT REAL TIME CLOCKRTC EXTERNALPOWER OUT 5V/12V Option name of this page CI SLOT because of Hong Kong CI Region SMD GASKET Page 1. Trouble Shooting Contents of LCD TV Standard Repair Process Main 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 output Check various voltages of PowerNo Video Board By 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 Cable External 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 RGB Stand-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 POWEROFFCPUABNORMAL Power 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 device 1. Remote controlR/C operating error D. General Function ProblemCheck & Repair Cable connection Connector solder Output signal Check input signal D. Function errorY Check technical Signal information input? - Fix information S/W Version Identify nose type E. Noise F. 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 Manual Press the IN-START with the remote controller for adjustment 1. Checking method for remote controller for adjustmentALL MODELS Version You can view 6 types of patterns using the ADJ Key A. Video errorColor error Appendix Exchange T-Con Board Appendix Exchange T-Con Board No Light Appendix Exchange PSULED driverDim Light No picture/Sound Ok A - 3/5 Un-repairable Cases In this case please exchange the module Appendix Exchange the ModulePanel Mura, Light leakage Press damage Un-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 method 1. Press the MENU button on the remote controller C. Audio errorNo audio/Normal videoChecking method 2. Select the AUDIO function of the Menu

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

Models: 42LT640H-ZA

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