LG 42LE5500 Schematic

1080P

Published October 8th, 2010

Direct View LCD

Training

42LE5500

LED Backlights

LCD-DV Troubleshooting

42" Class Full HD 1080P

LCD TV (42" diagonally)

OUTLINE

Preliminary Section:

Disassembly Section: Removal of Circuit Boards

Contact Information, Preliminary Matters, Specifications, LCD Overview, General Troubleshooting Steps, Signal Distribution, Disassembly Instructions and Voltages

Troubleshooting Section:

• Switch Mode Power Supply with LED Backlight Driver Board

• Main Board

• Ft Control Board

• Soft Touch Keys

• Speakers

Board Operation Troubleshooting of :

October 2010 LCD TV 42LE5500

Overview of Topics to be Discussed

42LE5500 LCD Direct View Display

This Section will cover Contact Information and remind the Technician of Important Safety Precautions for the Customers Safety as well as the Technician and the Equipment.

Basic Troubleshooting Techniques which can save time and money sometimes can be overlooked. These techniques will also be presented.

This Section will get the Technician familiar with the Disassembly, Identification and

Section 1

Layout of the LCD Display Panel.

At the end of this Section the Technician should be able to Identify the Circuit Boards and have the ability and knowledge necessary to safely remove and replace any Circuit Board or Assembly.

October 2010 LCD TV 42LE5500

IMPORTANT SAFETY NOTICE

CAUTION

Preliminary Matters (The Fine Print)

The information in this training manual is intended for use by persons possessing an adequate background in electrical equipment, electronic devices, and mechanical systems. In any attempt to repair a major Product, personal injury and property damage can result. The manufacturer or seller maintains no liability for the interpretation of this information, nor can it assume any liability in conjunction with its use. When servicing this product, under no circumstances should the original design be modified or altered without permission from LG Electronics. Unauthorized modifications will not only void the warranty, but may lead to property damage or user injury. If wires, screws, clips, straps, nuts, or washers used to complete a ground path are removed for service, they must be returned to their original positions and properly fastened.

To avoid personal injury, disconnect the power before servicing this product. If electrical power is required for diagnosis or test purposes, disconnect the power immediately after performing the necessary checks. Also be aware that many household products present a weight hazard. At least two people should be involved in the installation or servicing of such devices. Failure to consider the weight of an product could result in physical injury.

October 2010 LCD TV 42LE5500

Regulatory Information

ESD Notice

(Electrostatic Static Discharge)

Today’s sophisticated electronics are electrostatic discharge (ESD) sensitive. ESD can weaken or damage the electronics in a manner that renders them inoperative or reduces the time until their next failure. Connect an ESD wrist strap to a ground connection point or unpainted metal in the product. Alternatively, you can touch your finger repeatedly to a ground connection point or unpainted metal in the product. Before removing a replacement part from its package, touch the anti-static bag to a ground connection point or unpainted metal in the product. Handle the electronic control assembly by its edges only. When repackaging a failed electronic control assembly in an anti-static bag, observe these same precautions.

This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a residential installation. This equipment generates, uses, and can radiate radio frequency energy, and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures: Reorient or relocate the receiving antenna; Increase the separation between the equipment and the receiver; Connect the equipment to an outlet on a different circuit than that to which the receiver is connected; or consult the dealer or an experienced radio/TV technician for help.

(Electrostatic Static Discharge)

October 2010 LCD TV 42LE5500

LG Contact Information

Customer Service (and Part Sales) (800) 243-0000 Technical Support (and Part Sales) (800) 847-7597 USA Website (GSFS) http://gsfs-america.lge.com Customer Service Website http://www.us.lgservice.com Knowledgebase Website http://lgtechassist.com LG Web Training https://lge.webex.com LG CS Academy http://ln.lge.com/ilearn

LCD-DV:

PLASMA:

PDP Panel Alignment Handbook, Schematics with Bookmarks

32LG40, 32LH30, 37LH55, 42LG60, 42LG70, 42LH20, 42LH40, 42LH50, 42LH90, 42SL80, 47LG90, 47LH85, 42LE5500, 47LE8500

42PG20, 42PJ350, 42PQ20, 42PQ30, 50PG20, 50PJ350, 50PK250, 50PK750, 50PS80, 50PS60, 60PK750, 60PS11, 60PS60, 60PS80

Also available on the Plasma Page:

Plasma Control Board ROM Update (Jig required)

Published September 2010 by LG Technical Support and Training

LG Electronics Alabama, Inc.

201 James Record Road, Huntsville, AL, 35813.

New: 2010 Models Software Downloads Technical Assistance

Presentations with Audio/Video and Screen Marks

http://136.166.4.200

New Training Materials on

the Learning Academy site

October 2010 LCD TV 42LE5500

LCD Direct View Overview

Safety and Handling Regulations

1. Approximately 20 minute pre-run time is required before making any picture performance adjustments from the Menu.

2. Refer to the Voltage/Current silk screening on the Switch Mode Power Supply.

3. C-MOS circuits are sensitive to static electricity. Use caution when dealing with these IC and circuits.

4. Exercise care when making voltage and waveform checks to prevent costly short circuits from damaging the unit.

5. Be cautious of lost screws and other metal objects to prevent a possible short in the circuitry.

Checking Points to be Considered

1. Check the appearance of the Replacement Panel and Circuit Boards for both physical damage and part number accuracy.

2. Check the model label. Verify model names and board model matches.

3. Check details of defective condition and history. Example: Oscillator failure dead set, etc…

October 2010 LCD TV 42LE5500

Basic Troubleshooting Steps

Define, Localize, Isolate and Correct

•Define the failure. Use your senses Sight, Smell, Touch and Hearing. Look for burned parts and check for possible overheated components. Capacitors will sometimes leak dielectric material and give off a distinct odor. Frequency of power supplies will change with the load, or listen for relay closing etc. Observation of the front Power LED may give some clues.

•Localize checked and after giving a thorough examination using your senses the first check should always be the DC Supply Voltages to those circuits under test. Always confirm the supplies are not only the proper level but be sure they are noise free. If the supplies are missing check the resistance for possible short circuits.

•Isolate Oscilloscope to make a final determination of the failure. Look for correct Amplitude Phasing and Timing of the signals also check for the proper Duty Cycle of the signals. Sometimes “glitches” or “road bumps” will be an indication of an imminent failure.

Look at the symptom carefully and determine what circuits could be causing

After carefully checking the symptom and determining the circuits to be

To further isolate the failure, check for the proper waveforms with the

•Correct check the DC Supplies for proper levels. Make all necessary adjustments and lastly always perform a Safety AC Leakage Test before returning the product back to the Customer.

The final step is to correct the problem. Be careful of ESD and make sure to

October 2010 LCD TV 42LE5500

42LE5500 PRODUCT INFORMATION SECTION

This section of the manual will discuss the specifications of the

42LE5500

LCD Direct View Display

October 2010 LCD TV 42LE5500

Wireless Media Box

Wireless Media Box (Sold Separately)

The Wireless Media box communicates to the television via a wireless receiver

called a “Dongle”. The Dongle attaches to the Television via two connections:

1. HDMI Cable from the Dongle to the TV to transfer Audio and Video Signals.

2. Wired Remote cable between the TV and Dongle for Control Functions.

Media Box

Wired Remote to control the Media Box

Wireless Receiver/Transmitter

“Dongle”

Attaches via Velcro to

the back of the set

HDMI

TV A/V Inputs

October 2010 LCD TV 42LE5500

Wireless LAN (DLNA Adaptor)

Wireless LAN (Sold Separately)

Using the LG Wireless LAN for Broadband/1DLNA Adaptor, which is sold separately, allows the TV to connect to a wireless LAN network. The DLNA adaptor attaches to the Television via either of the two USB connections:

1(DLNA: Digital Living Network Alliance)

Side A/V Inputs

DLNA Adaptor

“Dongle”

Wireless Router

October 2010 LCD TV 42LE5500

Basic Specifications

Key TV Features

• LED Plus w/Local Dimming

• NetCast™ Entertainment Access* (Wi-Fi® Ready)

• Wireless 1080p Ready*

• DLNA Certified®

• TruMotion 120Hz

• Full HD 1080p Resolution

• 5M:1 Dynamic Contrast Ratio

• Picture Wizard II (Easy Picture Calibration)

• Smart Energy Saving

• ENERGY STAR® Qualified

• Intelligent Sensor

• AV Mode II (Cinema, Sports, Game)

• Clear Voice II

• ISFccc® Ready

• 24P Real Cinema

• USB 2.0 (JPEG, MP3, DivX HD)

• DivX® HD

• 4 HDMI™ V.1.3 w/Deep Color

• SIMPLINK™ Connectivity

• Dolby® Digital 5.1 Decoder

• Infinite Sound

October 2010 LCD TV 42LE5500

Logo Familiarization Page 1 of 4

LED Plus

Prepare to be dazzled. Tired of dark scenes or dull colors? LG’s LED Plus technology provides even greater control of brightness through local dimming to deliver amazing clarity and color detail, as well as a more energy efficient TV compared to conventional TVs.

TruMotion 120Hz

See sports, video games and high-speed action with virtually no motion blur and in crystal clarity with LG’s TruMotion 120Hz technology. Now your TV can keep up with the fastest moving scenes.

NetCast

Entertainment on tap. NetCast Entertainment Access brings the best Internet services direct to your TV—no computer required. Instantly access movies and TV shows, news and weather and the world’s largest library of HD movies in 1080p.

October 2010 LCD TV 42LE5500

Logo Familiarization Page 2 of 4

FULL HD RESOLUTION 1080P HD Resolution Pixels: 1920 (H) × 1080 (V) Enjoy twice the picture quality of standard HDTV with almost double the pixel resolution. See sharper details like never before. Just imagine a Blu-ray disc or video game seen on your new LG Full HD 1080p TV.

HDMI (1.3 Deep Color) Digital multi-connectivity

HDMI (1.3 Deep color) provides a wider bandwidth (340MHz,

10.2Gbps) than that of HDMI 1.2, delivering a broader range of colors, and also drastically improves the data-transmission speed.

Invisible Speaker Personally tuned by Mr. Mark Levinson for LG

TAKE IT TO THE EDGE newly introduces ‘Invisible Speaker’ system, guaranteeing first class audio quality personally tuned by Mr. Mark Levinson, world renowned as an audio authority. It provides Full Sweet Spot and realistic sound equal to that of theaters with its Invisible Speaker.

AV Mode "One click" Cinema,

TAKE IT TO THE EDGE is a true multimedia TV with an AV Mode which allows you to choose from 4 different modes of Cinema, Sports and Game by a single click of a remote control.

THX

Cinema, Sport, Game mode.

October 2010 LCD TV 42LE5500

Logo Familiarization Page 3 of 4

Clear Voice Clearer dialogue sound

Automatically enhances and amplifies the sound of the human voice frequency range to provide high-quality dialogue when background noise swells.

Save Energy, Save Money

It reduces the plasma display’s power consumption. The default factory setting complies with the Energy Star requirements and is adjusted to the comfortable level to be viewed at home. (Turns on Intelligent Sensor).

Save Energy, Save Money

Home electronic products use energy when they're off to power features like clock displays and remote controls. Those that have earned the ENERGY STAR use as much as 60% less energy to perform these functions, while providing the same performance at the same price as less-efficient models. Less energy means you pay less on your energy bill. Draws less than 1 Watt in stand by.

October 2010 LCD TV 42LE5500

Logo Familiarization Page 4 of 4

Wireless Ready

Wireless 1080p Connectivity lets you cut loose from messy wires and still get a stunning Full HD picture. Disclaimer: Wireless media kit required and sold separately.

Picture Wizard

Get easy self-calibration with on-screen reference points for key picture quality elements such as black level, color, tint, sharpness and backlight levels. Take the guesswork out of picture adjustments with this simple-to-use feature. It's not actually magic, but it will sure seem that way.

5M:1 Dynamic Contrast Ratio

Worrying about dark scenes is a thing of the past. The mega contrast ratio of 5,000,000:1 delivers vivid colors and deep blacks.

Intelligent Sensor

The Intelligent sensor will monitor the room lighting environment. When the room lights go out, the TV will automatically adjust the picture for the best view enjoyment.

October 2010 LCD TV 42LE5500

42LE5500 Remote Control

p/n AKB72914003

TOP PORTION

BOTTOM PORTION

October 2010 LCD TV 42LE5500

Accessing the Service Menu

To access the Service Menu.

1) You must have either Service Remote. p/n 105-201M or p/n MKJ39170828

2) Press “In-Start”

3) A Password screen appears.

4) Enter the Password.

Note: A Password is required to enter the

Service Menu. Enter; 0000

105-201M

Note: If 0000 does not work use 0413.

October 2010 LCD TV 42LE5500

MKJ39170828

TV Rear Input / Output Jacks

LAN

Rear In/Out Jacks

USB1 or USB2 for Software

Upgrades, Wireless Dungle,

Music and Photos

Component or

Composite

Video/Audio 3

Side In/Out

USB 2

USB 1

Wireless Media Box

Remote Jack

MAIN BOARD

Rear and Side

Input/Output locations

Head

Phones

HDMI 4

October 2010 LCD TV 42LE5500

Software Updates (New and Changed Functions)

A wireless Internet Connection will work for Automatic Software Downloads., however if there are problems completing download, a Wired Internet Connection is preferred

For network setup assistance, press the green button for the Simple Manual

Bring up the Customer’s Menu then Press the Red button on Remote

With Software Update Highlighted, Press Select on Remote

Continue on next page

Scroll down to item 9 Network Connections

October 2010 LCD TV 42LE5500

Software Updates (New and Changed Functions) Continued

Automatic Internet Software Update

- Off : Automatic Software update does not work

- On : if new Software released, Software

Check Update version

- comparison current software version and Released software version

Additional TV Checks can be made by Scrolling down. Picture, Sound and Network Test

After completion of the test, a Pop up menu is displayed with preloaded back ground picture. Select NO if everything is OK.

download notice appears at turn on with two choices, Yes and Remind Me Later.

If you select Yes; Service call number, Model name, SW version and serial No. is displayed. Note: Confirm the “Suffix” of the model number.

If the Main board is replaced, the Model and Serial number must be reinserted into memory. See Model Number D/L.

October 2010 LCD TV 42LE5500

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