LG Electronics 47LE8500 - page 37

July 2010 LCD TV 47LE8500

37

TROUBLESHOOTING SECTION

TROUBLESHOOTING SECTION

Troubleshooting:

This section of the manual will discuss troubleshooting.

Upon completion of this section the Technician will have

a better understanding of how to diagnosis and resolve

problems.

Leandro Palmeira

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Contents

Main 47LE850047LE8500 OUTLINE 47LE8500 LCD Direct View Display Overview of Topics to be Discussed Section 1 Overview of Topics to be Discussed Page Page LG Contact InformationLG Contact Information LCD Direct View Overview Basic Troubleshooting Steps July 2010 LCD TV 47LE8500 Page WIRELESS SECTION (Wireless Media Box) July 2010 LCD TV 47LE8500 Wireless Media Box (Sold Separately) Page Basic Specifications Key TV Features 47LE8500 Logo Familiarization Page 1 of 4 47LE8500 Logo Familiarization Page 2 of 4 47LE8500 Logo Familiarization Page 3 of 4 47LE8500 47LE8500 Logo Familiarization Page 4 of 4 Logo Familiarization Page 4 of 4 Page Page TV Rear Input / Output JacksTV Rear Input / Output Jacks Page Software Updates (New and Changed Functions) Continued USB Automatic Software Download Instructions Manual Software Download: Page Page Service Menu: Downloading EDID Data Pg 2 of 2 47LE8500 Product Dimensions 27 July 2010 47LE8500 LCD-DV Page Removing the Back Cover Circuit Board Layout 47LE8500 Connector Identification Diagram MAIN BOARD POWER SUPPLY IR LED Speaker (Front Left) 47LE8500 Connector Identification Diagram (Main) TFT PANEL Speaker (Front Right) Soft Touch Keys INVERTER Power Supply Power Supply Board Removal Board Removal Removing the Main Board Disconnect P7500, P7501, P7900, P7901, P8000, P8200 and P8800 p/n EBU60842601 Removing the Inverter (Main) Board Removing the Inverter (Secondary) Board Removing Front IR Board Page Page Power Supply (SMPS) Board Layout 47LE8500 Power Supply Start Up Sequence POWER SUPPLY (SMPS) 9 1 4 47LE8500 Power Supply Start Up Sequence MAIN BOARD 2 5 66 8 July 2010 47LE8500 LCD-DV 47LE8500 Television Turn On Commands Circuit Drawing Q8002 Q8005 SMPS P201 MAIN Board P8000 Page Power Supply Board Backlights Test 2 Power Supply Connector P201 Voltage and Diode Check P201 Connector SMPS to Main P8000 P201 Connector Odd pins are on front row Power Supply Connector P204 / P205 Voltage and Diode Check Power Supply Connector SK101 Voltage and Diode Check SK101 F100 Power Supply F101 and F501 Voltage Checks INVERTER (LED BACKLIGHTS) SECTION Page Page 47LE8500 (IOP) Cartridge Breakdown 51 July 2010 50PK750 Plasma 47LE8500 IOP Block Structure Information 47LE8500 TFT PANEL LVDS To TFT Panel Backlight Blocks 9 Bars (24 Blocks Ea.) 216 Blocks V1 through V216 3 Extension Boards 9 Connectors Ea. 2 (13V) B+ pins Ea. 8 (V) Connections Ea. 216 (V) Connections 47 Explode View of the IOP Panel 47 Explode View of the IOP Panel 47LE8500 Inverter Main Layout CN5 CN3 CN2 CN4 DO NOT MEASURE CN1 47LE8500 Inverter Secondary Layout 47LE8500 Inverter (Main) B+ Routing A B 47LE8500 Inverter (Secondary) B+ Routing C Page July 2010 47LE8500 LCD-DV P-DIM (Global Dimming) Explained: P-DIM (May also be called PWM-DIM, VBR-B, PDS, BCM-VBR-B) 59 Inverter (Main) Fuse F1 and Inverter (Secondary) Fuse F101 Check Page Page LED Drive Signal and Troubleshooting Information Inverter Board Connector CN3 to Extension (Left) (Voltages) Inverter (Main and Secondary) CN1 and CN101(Voltage and Diode Ch Inverter (Main and Secondary) CN1 and CN101(Voltage and Diode Check) eck) Inverter (Main) CN11 & Inverter (Secondary) CN103 (Voltage and D Inverter (Main) CN11 & Inverter (Secondary) CN103 (Voltage and Diode Check) CN11 Inverter Main to Main P7900 iode Check) Inverter Run voltages taken with built in test pattern Page MAIN BOARD SECTION Page 47LE8500 Main Layout MAIN BOARD p/n: EBU60842601 QD 47LE8500 Main (Front Side) Component Voltages 71 47LE8500 Main (Back Side) Layout QD 47LE8500 Main (Back Side) Component Voltages 73 Main Board X9001 and X9000 Crystal Checks Main Board X8100 and X1001 Crystal Checks Main Board DC to DC Converter (Voltages for Panel) Checks Main Board Additional Panel Voltage Checks Main Board Connector P8000 to Power Supply Voltage and Diode Che Main Board Connector P8000 to Power Supply Voltage and Diode Check ck OSD Backlight setting and Intelligent Sensor (room light condition). Range 0.37V to 3.3V. P8000 Odd Pins Front Row Page Page Main Board P8200 to (Ft. IR/Intelligent Sensor) Voltage and Diod Main Board P8200 to (Ft. IR/Intelligent Sensor) Voltage and Diode Check e Check Main P7900 / P7901 (Voltage and Diode Check) P7900 Main to Inverter Main CN11 Inverter Run voltages taken with built in test pattern P7901 Main to Inverter Secondary CN103 Main Board Connector P8800 to Speakers Voltage and Diode Check IC8801 P8800 (1) Page FRONT (IR, INTELLIGENT SENSOR and MOVING LED) SECTION July 2010 LCD TV 47LE8500 FRONT (IR, INTELLIGENT SENSOR and MOVING LED) SECTION Front IR Board (Connections Identified) Front Board Connectors CON1, CON2 and CON3 Voltage and Diode Ch Front Board Connectors CON1, CON2 and CON3 Voltage and Diode Check eck Page Page P8800 P8200 Q8701 V169~V176 CN14 Leandro Palmeira 42LE8500 Inverter Main and Secondary Local Dimming Control Signals Waveforms CN11 INVERTER (MAIN) FROM P7900 MAIN BOARD CN103 INVERTER (SECONDARY) FROM P7901 MAIN BOARD