LG 32LG40 Series Installation guide

32LG40
32LG40
Direct View LCD
Model : 32LG40 32” CLASS
LCD HDTV w/ BUILT-IN DVD
PLAYER
(31.5" diagonal)

LCD DV 32LG40
2
OUTLINE
OUTLINE
• Main (Digital) Board
•T-CONBoard
•BallastBoard
Circuit Board Operation, Troubleshooting of :
• Switch mode Power Supply
Section 1
Section 2
Contact Information, Preliminary Matters, Specifications,
LCD Overview, General Troubleshooting Steps,
Signal Distribution, Disassembly Instructions and Voltages

LCD DV 32LG40
3
32LG40 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 remove and replace safely any Circuit Board or Assembly.
Overview of Topics to be Discussed
Overview of Topics to be Discussed

LCD DV 32LG40
4
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)

LCD DV 32LG40
5
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)

LCD DV 32LG40
6
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
Published March 2008 by LG Technical Support and Training
The responsible party for this device’s compliance is:
COMPLIANCE
COMPLIANCE
LG Electronics Alabama, Inc.
201 James Record Road,
Huntsville, AL, 35813.

LCD DV 32LG40
7
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: Oscillator failure dead set, etc…
1. Approximately 20 minute pre-run time is required before any adjustments are performed.
2. Refer to the Voltage Sticker on the Switch Mode Power Supply silk screening. (+/- ½ volt).
3. Be cautious of electric shock from the Backlight section, it uses high voltage AC. 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 sensitive to static electricity. Use caution when dealing with these IC and circuits.
5. Exercise care when making voltage and waveform checks to prevent costly short circuits from damaging the unit.
6. Be cautious of lost screws and other metal objects to prevent a possible short in the circuitry.
7. The Tubes do contain a small amount of Mercury. Caution is necessary for disposal.
Checking Points to be Considered
SECTION 1:
SECTION 1: LCD OVERVIEW LCD OVERVIEW

LCD DV 32LG40
8
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.

LCD DV 32LG40
9
This section of the manual will discuss the specifications of the 32LG40
“Thin” LCD Direct View Display Panel.
32LG40 Product Information
32LG40 Product Information
Side View

LCD DV 32LG40
10
Basic Specifications
Basic Specifications
•720p HD Resolution
• 12,000:1 Dynamic Contrast Ratio
• Side-loading Progressive Scan DVD Player
• Super Multi-Format
• 3x HDMI™ 1.3
• AV Mode (Cinema, Sports, Game)
• Clear Voice
• SimpLink™ Connectivity
• Invisible Speaker System
• Expert Mode
• PC Input
• Swivel Stand (Manual)

LCD DV 32LG40
11
32LG40 HDTV Logo Familiarization Explained
32LG40 HDTV Logo Familiarization Explained
FORMATS
480I
480P
1080I
720P
1080P
Interlaced
Progressive
Interlaced
Progressive
Progressive
Interlaced
2 Fields to make a Frame
Progressive
Each Field is a Frame
Think of sync as the Panels “Refresh Rate”
240 Lines
480 Lines
540 Lines
720 Lines
1080 Lines
NTSC
SD
HD
HD
HD
BASIC
PIXEL COUNTS
PLASMA
1365 (H) ×768 (V)
LCD DV
1920 (H) x 1080 (V)
Possible Frame
Rates:
24FPS
30FPS
60FPS
HD RESOLUTION 720p HD Resolution Pixels: 1366 (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.

LCD DV 32LG40
12
Basic Specifications
Basic Specifications
INVISIBLE SPEAKER SYSTEM
LG’s 2008 line of TVs include a unique invisible speaker system, tuned by renowned audio
expert, Mr. Mark Levinson. Speakers are embedded in strategic spots behind the front
cabinet and use minute vibrations to turn the entire front bezel into the speaker system. The
result is a clean, polished look, and enhanced audio by increasing the “sweet spot” giving a
wider sound field.
BUILT-IN SIDE LOADING PROGRESSIVE SCAN DVD PLAYER
Save space with the built-in progressive scan DVD player. Side loading player upconverts
DVDs to near 720p resolution and features LG “Super-Multi” technology which plays back
almost any recordable disc based media.
LG SIMPLINK™ MULTI-DEVICE CONTROL
Allows for convenient control of other LG SimpLink products using the
existing HDMI connection.
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.

LCD DV 32LG40
13
Basic Specifications
Basic Specifications
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. Draws less than 1 Watt in stand by.

LCD DV 32LG40
14
Remote Control
Remote Control
1 2 3
4 5 6
7 8 9
0
VOL CH
FAV
MUTE
P
A
G
E
LG
TOP PORTION
BOTTOM PORTION

LCD DV 32LG40
15
Accessing the Service Menu
Accessing the Service Menu
REMOTE
TOP PORTION
SIDE KEYS
Note: Dependant upon the Software Version, a Password
may be required to enter the Service Menu.
If a password is required, enter
0000
To access the Service Menu.
1) Turn the Set On
2) Simultaneously, Press and
“Hold” the Menu Key on the
Side Key pad and Press and
“Hold” the Menu Key on the
Remote approximately 5
seconds.
3) If Customer’s Menu appears,
continue to hold until it
disappears.
4) The Service Menu appears

LCD DV 32LG40
16
Side Input Jacks
Rear and Side Input Jacks
Rear and Side Input Jacks
USB
HDMI
Composite
A/V
Main PWB
Orientation
Component
Y Pr/Pb
Optical AudioRGB (PC) Audio
RGB (PC)
HDMI
RS232
Service Only
Remote
In
Audio
Out
Composite
Current Software Release
32LG40-UA-v03.12_080711_Download.epk

LCD DV 32LG40
17
Side Input Jacks
Software release 7/10/08
Software release 7/10/08
USB
Service Bulletin: 0IVL20080332
Current Software Release
32LG40-UA-v03.12_080711_Download.epk
Symptoms
1) When tuned to CADTV 1-1, TV Set Locks-up
(Frozen, will not respond to the remote or Video/Audio).
2) DTV Closed captions Lock-up on Channel 20 in
Washington DC (DTVCC Service1 On => Video
Freezes or TV set reboots).
Update the firmware using a USB flash drive. For warranty work, you have to write this
service bulletin number 0IVL20080332 in the remark or description cell.

LCD DV 32LG40
18
32LG40 Product Measurements
32LG40 Product Measurements

LCD DV 32LG40
19
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.
TROUBLESHOOTING SECTION
TROUBLESHOOTING SECTION

LCD DV 32LG40
20
Removing the Back Cover
Removing the Back Cover
The Stand does not need to be removed. Remove the 18 screws shown by arrows.
Pay attention to the size and type of screw as there are many different types.
Putting in the improper screw when reassembling may Cause damage.