LG 47LX9500 User manual
LCD-DV Troubleshooting
47" Class Full HD 1080P
LCD TV (47" diagonally)
47LX9500
47LX9500
LED Backlights
1080P
Direct View LCD
Training
Published September 10
th
, 2010
September LCD TV 47LX9500
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OUTLINE
OUTLINE
•T-CON/3D Board
•Switch Mode Power Supply
Preliminary Section:
Troubleshooting Section: Board Operation Troubleshooting of :
Contact Information, Preliminary Matters, Specifications,
LCD Overview, General Troubleshooting Steps,
Signal Distribution, Disassembly Instructions and Voltages
•Main Board
•Inverter Boards Main and Secondary (LED Backlight Drivers)
•Soft Touch Keys
Disassembly Section: Removal of Circuit Boards
•Ft Control Board
•Speakers
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47LX9500 LCD Direct View Display
Section 1
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
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.
Overview of Topics to be Discussed
Overview of Topics to be Discussed
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IMPORTANT SAFETY NOTICE
IMPORTANT SAFETY NOTICE
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.
CAUTION
CAUTION
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.
Preliminary Matters (The Fine Print)
Preliminary Matters (The Fine Print)
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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.
Regulatory Information
Regulatory Information
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.
ESD Notice
ESD Notice
(Electrostatic Static Discharge)
(Electrostatic Static Discharge)
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Contact Information
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 us.lgservice.com
Knowledgebase Website lgtechassist.com
LG Web Training lge.webex.com
LG CS Academy lgcsacademy.com
Published September 2010 by LG Technical Support and Training
LG Electronics Alabama, Inc.
201 James Record Road, Huntsville, AL, 35813.
32LG40, 32LH30, 37LH55, 42LG60, 42LG70, 42LH20, 42LH40, 42LH50, 42LH90, 42SL80,
47LG90, 47LH85, 47LX9500, 47LX9500
42PG20, 42PQ20, 42PQ30, 50PG20, 50PJ350, 50PK750, 50PS80, 50PS60, 60PK750,
60PS11, 60PS60, 60PS80
LCD-DV:
PLASMA:
Also available on the Plasma Page:
PDP Panel Alignment Handbook, Schematics with Bookmarks
Plasma Control Board ROM Update (Jig required)
Presentations with Audio/Video
and Screen Marks
New Training Materials on
New Training Materials on
the Learning Academy site
the Learning Academy site
http://136.166.4.200
New: Software Downloads
Technical Assistance
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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.
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…
Checking Points to be Considered
LCD Direct View Overview
LCD Direct View Overview
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Basic Troubleshooting Steps
Basic Troubleshooting Steps
Define, Localize, Isolate and Correct
•Define Look at the symptom carefully and determine what circuits could be causing
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 After carefully checking the symptom and determining the circuits to be
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 To further isolate the failure, check for the proper waveforms with the
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.
•Correct The final step is to correct the problem. Be careful of ESD and make sure to
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.
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This section of the manual will discuss the specifications of the
47LX9500
LCD Direct View Display
47LX9500 PRODUCT INFORMATION SECTION
47LX9500 PRODUCT INFORMATION SECTION
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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.
Wireless Media Box
Wireless Media Box
Media Box
Wireless Receiver/Transmitter
“Dongle”
Attaches via Velcro to
the back of the set
Wired Remote to control the Media Box
HDMI
TV A/V Inputs
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Table of contents
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