LG 50PG20 Series Installation guide

1
Advanced Single Scan Troubleshooting
Training Manual
50PG20 Plasma Display
50PG20 Plasma Display
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720p

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Overview of Topics to be Discussed
• Y SUS Board
• Z SUS Board
• Y Drive Boards
• Control Board
• X Drive Boards
Circuit Board Operation, Troubleshooting and Alignment of :
• Switch mode Power Supply
• Main Board
Section 1
Section 2
Contact Information, Preliminary Matters, Specifications,
Plasma Overview, General Troubleshooting Steps,
Disassembly Instructions, Voltage and Signal Distribution
OUTLINE
OUTLINE

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50PG20 Plasma 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 Plasma
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
ESD NOTICE NOTICE
(Electrostatic Static Discharge)
(Electrostatic Static Discharge)

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CONTACT INFORMATION
CONTACT INFORMATION
Customer Service (and Part Sales) [phone]
Technical Support (and Part Sales) [phone]
USA Website (GCSC) aic.lgservice.com
Customer Service Website us.lgservice.com
LG CS Academy lgcsacademy.com
LG Web Training lge.webex.com
Published March 2009 by LG Technical Support and Training
LG Electronics Alabama, Inc.
201 James Record Road,
Huntsville, AL, 35813.

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Safety & Handling Regulations
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: Y Board Failure, Mal-discharge on screen, etc.
1. Approximately 10 minute pre-run time is required before any adjustments are performed.
2. Refer to the Voltage Sticker inside the Panel when making adjustments on the Power Supply, Y SUS and Z SUS Boards.
Always adjust to the specified voltage level (+/- ½ volt). Unless otherwise noted.
3. Be cautious of electric shock from the PDP module since the PDP module uses high voltage, check that the Power Supply
and Drive Circuits are completely discharged because of residual current stored before Circuit Board removal.
4. C-MOS circuits are used extensively for processing the Drive Signals and should be protected from static electricity.
5. The PDP Module must be carried by two people. Always carry vertical NOT horizontal.
6. Also the Plasma television MUST be transported vertical NOT horizontal.
7. Exercise care when making voltage and waveform checks to prevent costly short circuits from damaging the unit.
8. Be cautious of lost screws and other metal objects to prevent a possible short in the circuitry.
Checking Points to be Considered
SECTION 1:
SECTION 1: PLASMA OVERVIEW PLASMA 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 50PG20 Advanced
Single Scan Plasma Display Panel.
50PG20 Product Information
50PG20 Product Information
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50PG20 Specifications
50PG20 Specifications
PLASMA HDTV
50” Class (49.9” diagonal)
• 720p HD Resolution
• Dual XD Engine™
• 20,000:1 Contrast Ratio
• Fluid Motion
• 3x HDMI™ V.1.3 with Deep Color
• AV Mode (Cinema, Sports, Game)
• Clear Voice
• LG SimpLink™ Connectivity
• Invisible Speaker System
• 100,000 Hours to Half Brightness (Typical)
• PC Input

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50PG20 Specifications Logo Familiarization
50PG20 Specifications Logo Familiarization
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.
HD RESOLUTION 720p HD Resolution Pixels: 1365 (H) × 768 (V)
High definition television is the highest performance segment of the
DTV system used in the US. It’s a wide screen, high-resolution video
image, coupled with multi-channel, compact-disc quality sound.
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.
Dual XD Engine
Realizing optimal quality for all images
One XD Engine optimizes the images from RF signals as another XD
Engine optimizes them from External inputs. Dual XD Engine presents
images with optimal quality two times higher than those of previous
models.

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50PG20 Specifications Logo Familiarization
50PG20 Specifications Logo Familiarization
AV Mode "One click" - Cinema, Sports, Game mode.
TAKE IT TO THE EDGE is a true multimedia TV with an AV Mode
which allows you to choose from 3 different modes of Movies, Video
Games and Sports by a single click of a remote control.
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
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.

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50PG20 Specifications Logo Familiarization
50PG20 Specifications Logo Familiarization
LG SIMPLINK™ MULTI-DEVICE CONTROL
Allows for convenient control of other LG SimpLink products using the
existing HDMI connection.
Tru-Surround is a sound-scheme that has the ability to take multi-
channel encoded sources, such as Dolby Digital, and reproduce the
multi-channel surround effect by just using two-speakers. The result is
not as impressive as true Dolby Digital 5.1 (the front and side surround
effects are impressive, but the rear surround effects fall a little short,
with the sense they are coming from just to rear of your head rather
than from the back of the room).
Dolby® Digital
In thousands of cinemas and millions of homes worldwide, Dolby
Digital is the reigning standard for surround sound technology in
general and 5.1-channel surround sound in particular.
FLUIDMOTION (180 Hz Effect)
Enjoy smoother, clearer motion with all types of programming such as sports
and action movies.
The moving picture resolution give the impression of performance of up to 3x
the panels actual refresh rate.

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PDP
180Hz
LCD
60Hz
Moving Picture Response Time is
16.5 milliseconds
(120Hz takes MPRT to 8.25ms)
Panel Response Time
is 4 to 8 milliseconds
Moving Picture Response Time is
5.44 milliseconds
Panel Response Time
is less than 1 millisecond
FluidMotion (180 Hz Effect)
Enjoy smoother, clearer motion with all types of programming such as sports and action movies.
The moving picture resolution give the impression of performance of up to 3x the panels actual refresh rate.
50PG20 Specifications
50PG20 Specifications FluidMotion FluidMotion Familiarization Familiarization

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50PG20 Remote Control
50PG20 Remote Control
TOP PORTION BOTTOM PORTION

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Rear and Side Input Jacks
Rear and Side Input Jacks

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1. Copy new software (xxx.bin) to root folder in USB storage.
2. Turn on the TV
3. Connect USB storage to USB port on TV.
4. After about 5 seconds and it shows on screen.
5. Select ‘START’ button.
<USB download main screen>
Your File name and version number will differ. Use this just for reference.
Software Upgrade (Automatic)
Software Upgrade (Automatic)
INFORMATION
Current Ver. 03.11
Update Ver. 03.14
merged_50PG20_UA_0314_PDP_56.bin
To start upgrading your TV set. Please follow the procedures.
1. Press an arrow key on your remote to reach START on the screen.
2. Press ENTER key on your remote to start downloading.
If you do not want to download the upgrade file, please press
the arrow key to reach CANCEL on the screen.
Then, press the ENTER key on your remote
▲▼FULL
Snapshot of Windows
Snapshot of Windows
®
®
Explorer screen
Explorer screen

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50PG20 Dimensions
50PG20 Dimensions

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This section of the manual will discuss Disassembly, Layout and Circuit
Board Identification, of the 50PG20 Advanced Single Scan Plasma Display Panel.
Upon completion of this section the Technician will have a better
understanding of the disassembly procedures, the layout of the printed
circuit boards and be able to identify each board.
DISASSEMBLY SECTION
DISASSEMBLY SECTION
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Removing the Back Cover
Removing the Back Cover
To remove the back cover, remove the 26 screws
(The Stand does not need to be removed).
Indicated by the arrows.
PAY CLOSE ATTENTION TO THE TYPE, SIZE AND LENGTH
Of the screws when replacing the back cover. Improper type can
damage the front.