LG L15V26 Installation guide

Service
Digital Display
TRAINING MANUAL
LCD DIRECTVIEW TELEVISION - 2006

Published February 2006 by LG Education & Product Engineering
Customer Service (and Part Sales): 1-800-243-0000
Technical Support (and Part Sales): 1-800-847-7597
USA Website: www.lgusa.com
Customer Service Website: us.lgservice.com
B2B Service Website: aic.lgservice.com
Training Website: www.LGCSAcademy.com
IMPORTANT SAFETY NOTICE
This manual was prepared for use only by properly trained audio-visual service technicians. 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. All components should be replaced only with types identical to those in the original
circuit and their physical location, wiring, and lead dress must conform to original layout upon completion of repairs. If any fuse (or Fusible
Resistor) in this TV receiver is blown, replace it only with the factory specified fuse type and rating. When replacing a high wattage resistor (Oxide
Metal Film Resistor, over 1W), keep the resistor 10mm away from PCB. Always keep wires away from high voltage or high temperature parts. Do not
attempt to modify this product in any way.
Special components are also used to prevent shock and fire hazard and are required to maintain safe performance. No deviations are allowed
without prior approval by LG Electronics. Service work should be performed only after you are thoroughly familiar with these safety checks and
servicing guidelines. Circuit diagrams may occasionally differ from the actual circuit used. This way, implementation of the latest safety and
performance improvement changes into the set is not delayed until the new service literature is printed.
GENERAL SAFETY GUIDANCE
An lsolation Transformer should always be used during the servicing of a receiver whose chassis is not isolated from the AC power line. Use a
transformer of adequate power rating to protect against personal injury from electrical shocks. It will also protect the receiver and its components
from being damaged by accidental shorts of the circuitry that may be inadvertently introduced during the service operation. Before returning the
receiver to the customer, always perform an AC leakage current check on the exposed metallic parts of the cabinet, such as antennas, terminals,
etc., to be sure the set is safe to operate without damage of electrical shock.
With the instrument AC plug removed from AC source, connect an electrical jumper across the two AC plug prongs. Place the AC switch in the on
position, connect one lead of ohm-meter to the AC plug prongs tied together and touch other ohm-meter lead in turn to each exposed metallic
parts such as antenna terminals, phone jacks, etc. If the exposed metallic part has a return path to the chassis, the measured resistance should be
between 1MΩand 5.2MΩ. When the exposed metal has no return path to the chassis the reading must be infinite. Any other abnormality that
exists must be corrected before the receiver is returned to the customer.
ELECTROSTATICALLY SENSITIVE DEVICES
Some semiconductor (solid-state) devices can be damaged easily by static electricity. Such components commonly are called Electrostatically
Sensitive (ES) Devices. Examples of typical ES devices are integrated circuits and some field-effect transistors and semiconductor “chip” compo-
nents. The following techniques should be used to help reduce the incidence of component damage caused by static electricity.
Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off any electrostatic charge on the body
by touching a known earth ground. Alternatively, obtain and wear a commercially available discharging wrist strap device, which should be
removed for potential shock reasons prior to applying power to the unit under test. After removing an electrical assembly equipped with ES
devices, place the assembly on a conductive surface such as an ESD mat, to prevent electrostatic charge buildup or exposure of the assembly. Use
only a grounded-tip soldering iron to solder or unsolder ES devices. Use only an anti-static solder removal device. Some solder removal devices
not classified as “anti-static” can generate electrical charges sufficient to damage ES devices. Do not use freon-propelled chemicals which can
generate electrical charge sufficient to damage ES devices. Do not remove a replacement ES device from its protective package until immediately
before you are ready to install it. Minimize bodily motions when handling unpackaged replacement ES devices (Otherwise, seemingly harmless
motion, such as the brushing together of your clothing or the lifting of your foot from a carpeted floor, can generate static electricity sufficient
to damage an ES device).
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 receiver; Connect the equipment into an outlet on a circuit different from that to which the
receiver is connected; Consult the dealer or an experienced radio/TV technician for help.
The responsible party for this device’s compliance is:
LG Electronics of Alabama, Inc.
201 James Record Road
Huntsville, AL 35824, USA
Digital TV Hotline: [phone]

Directview LCD Training 3Contents
TABLE OF CONTENTS
OVERVIEW..................................................5
INTRODUCTION ........................................ 5
MOUNTING INTERFACE .............................. 5
COMPUTER CONNECTION ............................ 6
REMOTES ................................................ 6
TERMINOLOGY ............................................7
VIEWING ANGLE ....................................... 7
IPS (IN-PLANE SWITCHING) ....................... 7
PEAK BRIGHTNESS ................................... 7
CONTRAST RATIO ...................................... 7
RESPONSE TIME ....................................... 7
A/V CONNECTIONS .................................... 8
THEORY .....................................................9
LIQUID CRYSTALS ..................................... 9
LIQUID CRYSTAL DISPLAY .......................... 9
LIQUID CRYSTAL PANEL ........................... 10
LCD VERSUS CRT .................................... 11
LCD VERSUS PLASMA .............................. 11
MODEL OVERVIEW ..................................... 12
MODEL NUMBERS ................................... 12
MODEL DESCRIPTIONS ............................. 15
CIRCUIT DESCRIPTIONS ............................. 20
15”CIRCUIT DESCRIPTIONS (L15V26) ........ 20
30”CIRCUIT DESCRIPTIONS (L30W26) ....... 23
32” CIRCUIT DESCRIPTIONS (CABLECARD MODELS)
28
FIRMWARE UPDATES .................................. 33
FIRMWARE UPDATES VIA MEMORY CARD ..... 33
DISASSEMBLY ........................................... 37
SMALL SCREEN MODELS ........................... 37
LARGE SCREEN MODELS - PART 1 .............. 37
LARGE SCREEN MODELS - PART 2 .............. 39
EXPLODED VIEWS ................................... 40
CABLECARD .............................................. 62
DIGITAL CABLE READY (DCR) .................... 62
CEA-NCTA AGREEMENT ............................. 62
TERMS ................................................. 63
VENDORS .............................................. 63
DCR ARCHITECTURE ................................ 64
HOST-CABLECARD INTERFACE ................... 64
IN-BAND/OOB SPECIFICATION ................... 66
CABLE MENU & MMI ............................... 67
DIGITAL CERTIFICATES DATA ..................... 70
CABLECARD RESET .................................. 70
EAS (EMERGENCY ALERT SYSTEM) .............. 70
HOST DIAGNOSTICS ................................ 71
ERROR REPORTING ................................. 71
CABLE CARD TROUBLESHOOTING ............... 72
IN-HOME TROUBLESHOOTING ................... 77
CABLECARD TROUBLESHOOTING ................ 80
TV GUIDE ................................................. 82
OVERVIEW ............................................ 82
OPERATION ........................................... 82
SYSTEM INFO ........................................ 83
SYSTEM FLOWCHART ............................... 85

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Directview LCD Training 5Overview
OVERVIEW
OVERVIEW
INTRODUCTION
All LCD TV models are module level repair in and out of warranty. They are
covered by a one year parts and labor warranty. For service, the end user
should call 1-800-243-0000 for complete shipping and handling
instructions. Refer to the last page of the owner’s manual for more warranty
information. For models under 30”, the Sevice Level is Factory Service
Repair. Larger models are Field Service. Although, warranty repair by an
ASC is approved in certain situations for smaller screen models. Contact
the LG Warranty department for more information.
Most models are similiar in function and internal layout with the exception of models over 23". For
example, the 30" inch LCD has more fluorescent lamps than normal (16 lamps) and some additional
user functions.
Note that not all models support HDTV (High Definiton Television). The 10”, 13”, and 20” models do
not support HDTV, but 20” models do support EDTV (Enhanced Definiton Television). The section on
Models has more information about the specifications of each model.
MOUNTING INTERFACE
The Video Electronics Standards Association (VESA) Flat Display Mounting Interface Standard (FDMI)
outlines mounting interface standards for flat-panel displays. VESA FDMI Standards are 75 x 75 mm,
100 x 100 mm, and 100 x 200 mm mounting hole pattern with 4, 4 mm x 10 mm screws. Most new
models feature a VESA mount, except large screen models. Large screen models use mounting hole
patterns similar to PDPs.
75MM MOUNT
10” Models
100MM MOUNT
13” to 23”
200MM MOUNT
26” to 32” Models
NO VESA MOUNT
37, 42, & 55” models
100mm
100mm
10mm
4mm