Zenith LCD TV L15V24S Service Manual

SERVICE MANUAL

Product Type: LCD TV Chassis: ML-024A Manual Series: Manual Part #: Model Line: Product Year: 2002

L15V26C L15V24S

Model Series:

CONTENTS

Description of Controls .................................................4

Specifications.............................................................10

Adjustment Instructions...............................................14

Diagrams ...................................................................16

Parts List ...................................................................19

Schematics ....................................................................

Published June 2002

by Technical Publications

Zenith Electronics Corporation

201 James Record Road

Huntsville, Alabama 35824-1513

Printed in Korea

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PRODUCT SAFETY

IMPORTANT SAFETY NOTICE

This manual was prepared for use only by properly trained audiovisual service technicians. When servicing this product, under no circumstances should the original design be modified or altered without permission from Zenith Electronics Corporation. 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.

Special components are also used to prevent shock and fire hazard. These components are indicated by the letter “x” included in their component designators and are required to maintain safe performance. No deviations are allowed without prior approval by Zenith Electronics Corporation. 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.

CAUTION: Do not attempt to modify this product in any way.

Never perform customized installations without manufacturer’s approval. Unauthorized modifications will not only void the warranty, but may lead to property damage or user injury.

GENERAL 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.

LEAKAGE CURRENT COLD CHECK (ANTENNA COLD CHECK)

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 1MΩ and 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” components. The following techniques should be used to help reduce the incidence of component damage caused by static electricity.

1. 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.

2. 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.

3. Use only a grounded-tip soldering iron to solder or unsolder ES devices.

4. 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.

5. Do not use freon-propelled chemicals. These can generate electrical charge sufficient to damage ES devices.

6. Do not remove a replacement ES device from its protective package until immediately before you are ready to install it. (Most replacement ES devices are packaged with leads electrically shorted together by conductive foam, aluminum foil, or comparable conductive material.)

7. Immediately before removing the protective material from the leads of a replacement ES device, touch the protective material to the chassis or circuit assembly into which the device will be installed.

Caution: Be sure no power is applied to the chassis or circuit, and observe

all other safety precautions.

8. 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:

Zenith Electronics Corporation 201 James Record Road Huntsville, AL 35824, USA Digital TV Hotline: 1-800-243-0000

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DESCRIPTION OF CONTROLS...........................................4

SPECIFICATIONS...............................................................10

ADJUSTMENT INSTRUCTION...........................................14

BLOCK DIAGRAM...............................................................16

EXPLODED VIEW...............................................................18

EXPLODED VIEW PARTS LIST.........................................19

REPLACEMENT PARTS LIST............................................20

SCHEMATIC DIAGRAM..........................................................

PRINTED CIRCUIT BOARD ...................................................

TABLE OF CONTENTS

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DESCRIPTION OF CONTROLS

Front of the

Front of the TVTV

Side Control Panel

TV/Video Button

Enter Button

Channel Buttons

On/Off Button

Menu Button

Volume Buttons

Remote Control Sensor

Power/Standby indicator

Illuminates brightly when the TV is in standby mode. Dims when the TV is switched on.

L15V24S

vol

enter

tv/video

on/off

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DESCRIPTION OF CONTROLS

Power Cord Socket

- This TV operates on AC power. Never attempt to operate the TV on DC power.

Antenna Input

RS-232C Port

Headphone

Jack

Audio/Video

Input

S-Video Input

PC Input

PC Sound

Connection Panel

Back of the

Back of the TVTV

RS-232CAC INPUT

H/P

S-VIDEO

VIDEO IN

RLVIDEO AUDIO(MONO)

PC INPUT ANT IN

+75 Ω

SOUND(120V) INPUT

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DESCRIPTION OF CONTROLS

power

apc

mute

sleep

enter

vol vol

tv/video

2 3 5 64 8 97

mts

fcr

memory/erase

a.prog

flashbk dasp

TV/VIDEO

CLOSED CAPTIONS MUTE

ENTER

VOLUME (

F G

)

SLEEP

POWER

NUMBER

APC

MTS

FCR

AUTO PROGRAM

DASP FLASHBK

MEMORY/ERASE

Remote Control Buttons

CHANNEL (

)

l Press the FLASHBK button to view the last

program you were watching.

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Front of the

Front of the TVTV

Side Control Panel

TV/Video Button

Enter Button

Channel Buttons

On/Off Button

Menu Button

Volume Buttons

Remote Control Sensor

Power/Standby indicator

Illuminates brightly when the TV is in standby mode. Dims when the TV is switched on.

L15V26C

DESCRIPTION OF CONTROLS

vol

enter

tv/video

on/off

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DESCRIPTION OF CONTROLS

Power Cord Socket

- This TV operates on

AC power. Never attempt to operate the TV on DC power.

Antenna Input

DVD/DTV IN (Component (480i/480p,720p,1080i) Input

Headphone Jack

Audio/Video

Input

S-Video Input

PC Input

PC Sound

Connection Panel

Back of the

Back of the TVTV

AC INPUT

COMPONENT(480i/480p/720p/1080i)

DVD/DTV IN

H/P

S-VIDEO

VIDEO IN

RLVIDEO AUDIO(MONO)

ANT INPC INPUT

+75 Ω

SOUND(120V)

+ 18 hidden pages