LG DU-42PX12X, DU-42PX12XC Service Manual

PLASMA TV

SERVICE MANUAL

CAUTION

BEFORE SERVICING THE CHASSIS,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

CHASSIS :AF-044A

MODEL : DU-42PX12X DU-42PX12XC

CANADA : http//biz.lgservice.com
USA : http//www.lgservice.com

: http//lgservice.com/techsup.html

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SAFETY PRECAUTIONS

Many electrical and mechanical parts in this chassis have special safety-related characteristics. These parts are identified by in
the Schematic Diagram and Replacement Parts List.
It is essential that these special safety parts should be replaced with the same components as recommended in this manual to
prevent X-RADIATION, Shock, Fire, or other Hazards.
Do not modify the original design without permission of manufacturer.

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
as this protects the technician from accidents resulting in
personal injury from electrical shocks.

It will also protect the receiver and it's components from being
damaged by accidental shorts of the circuitary that may be
inadvertently introduced during the service operation.

If any fuse (or Fusible Resistor) in this monitor is blown, replace
it with the same specified type.

When replacing a high wattage resistor (Oxide Metal Film
Resistor, over 1W), keep the resistor 10mm away from PCB.

Keep wires away from high voltage or high temperature parts.

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 positioin, 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.
An other abnormality exists that must be corrected before the
receiver is returned to the customer.

Leakage Current Hot Check (See below Figure)

Plug the AC cord directly into the AC outlet.

Do not use a line Isolation Transformer during this check.

Connect 1.5K/10watt resistor in parallel with a 0.15uF capacitor
between a known good earth ground (Water Pipe, Conduit, etc.)
and the exposed metallic parts.
Measure the AC voltage across the resistor using AC
voltmeter with 1000 ohms/volt or more sensitivity.
Reverse plug the AC cord into the AC outlet and repeat AC
voltage measurements for each esposed metallic part. Any
voltage measured must not exceed 0.75 volt RMS which is
corresponds to 0.5mA.
In case any measurement is out of the limits sepcified, there is
possibility of shock hazard and the set must be checked and
repaired before it is returned to the customer.

Leakage Current Hot Check circuit

CANADA: LG Electronics Canada, Inc. 550 Matheson

Boulevard East Mississauga, Ontario L4Z 4G3

USA : LG Customer Interactive Center

P.O.Box 240007, 201 James Record Road Huntsville,
AL 35824
Digital TV Hotline [phone]

1.5 Kohm/10W

To Instrument's
exposed
METALLIC PARTS

Good Earth Ground
such as WATER PIPE,
CONDUIT etc.

AC Volt-meter

IMPORTANT SAFETY NOTICE

0.15uF

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SPECIFICATIONS.................................................................4

DESCRIPTION OF CONTROLS...........................................5

ADJUSTMENT INSTRUCTIONS ..........................................8

BLOCK DIAGRAM...............................................................12

EXPLODED VIEW...............................................................14

EXPLODED VIEW PARTS LIST.........................................15

REPLACEMENT PARTS LIST............................................16

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

PRINTED CIRCUIT BOARDS.................................................

TABLE OF CONTENTS

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• The specifications shown above may be changed without prior notice for quality improvement.

MODEL

AC100-240V ~ 60Hz

NTSC-M, ATSC

VHF 2 ~ 13, UHF 14 ~ 69, CATV 1 ~ 125, CADTV 1 ~ 135. DTV 2 ~ 69

75 Ω

1024 x 768 (Dot) 1366 x 768 (Dot)

16,770,000 (256 steps of each R, G and B)

32 ~ 104°F (0 ~ 40°C)

Less than 80%

6561 feet (2000m)

41 / 1040

27.5 / 699.5

3.7 / 95

76.1 / 34.5

Width (inches / mm)

Height (inches / mm)

Depth (inches / mm)

Weight (pounds / kg)

Power requirement

Television System

Program Coverage

External Antenna Impedance

Resolution

Color

Operating Temperature Range

Operating Humidity Range

Maximum Elevation

DU-42PX12X

48.3 / 1226.2

30.6 / 778

3.9 / 99

98.1 / 44.5

DU-50PX10

SPECIFICATIONS

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Controls

Controls

ON/OFF

TV/VIDEO

MENU

VOL CH

- This is a simplified representation of front panel.
Image may be somewhat different from your TV.

- This manual explains the features available on the DU-50PX10 series TVs.

Front Panel Controls

Front Panel Controls

ON/OFF Button

Remote Control Sensor

VOLUME (

FF,GG

) Buttons

Power Standby Indicator

Illuminates red in standby mode,
Illuminates green when the TV is
turned on.

CHANNEL (EE, DD) Buttons

MENU Button

TV/VIDEO Button

DESCRIPTION OF CONTROLS

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Connection Options

Connection Options

R

S-VIDEO VIDEO

L / MONO

AUDIO

A/V 2

REMOTE

CONTROL

RS-232C INPUT

(CONTROL/SERVICE)

AC INPUT

AUDIO INPUT

COMPONENT 2

COMPONENT 1

R L

DIGITAL AUDIO

(OPTICAL)

DVI

INPUT

COMPONENT1
INPUT

OUTPUT

AUDIO INPUT

DVI INPUT
(PC/DTV INPUT)

RGB INPUT

(PC/DTV INPUT)

VIDEO INPUT

DVD
/DTV
INPUT

MONITOR

OUTPUT

A/V

INPUT 1

AUDIO

R L

(MONO)

VIDEO

S-VIDEO

Antenna 1
Analog/DTV

Antenna 2
DTV

Back Connection Panel

Back Connection Panel

Antenna 1-2 Inputs

Connect cable or antenna signals to the

TV, either directly or through your cable

box. For DTV use Antenna 2 only.

DVI Input/Audio Input/RGB
Input

Connect the monitor output con­nector from a PC to the appro­priate input port.

Digital Audio (DVI: Digital Visual

Interface/Component1) Input/

Digital Audio Output

Connect digital audio from various types

of equipment. Note: In standby mode,

these ports will not work.

Audio/Video Input 1

Connect audio/video out-

put from an external

device to these jacks.

DVD/DTV Input (Component
1-2)

Connect a component
video/audio device to these
jacks.

Monitor Output

Connect a second TV or

Monitor.

Remote Control
Port

Connect your wired
remote control here.

S-Video Input

Connect S-Video out from an
S-VIDEO device to the S­VIDEO input.

Power Cord Socket

This TV operates on an AC power. The voltage is indi-

cated on the Specifications page. Never attempt to oper-

ate the TV on DC power.

- This manual explains the features available on the DU-50PZ60/70 series TVs.

S-VIDEO Input

A connection available to provide better
picture quality than the video input.

VIDEO Input

Connects the video signal from a video
device.

AUDIO Input

Use to connect to hear stereo sound
from an external device.

RS-232C INPUT
(CONTROL/SERVICE) PORT

Connect to the RS-232C port
on a PC.

DESCRIPTION OF CONTROLS

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- When using the remote control, aim it at the remote control sensor on the TV.

LIGHT

TV/VIDEO

MODE

COMP/RGB/DVI

MUTE

SURF

VOL CH

INFO

SAP

RATIO

CC

MENU

SOUND VIDEO

EXIT

PLAY PAUSE STOP RECORD

PIP PIPCH- PIPCH+ PIPINPUT

FREEZE

ADJUST

OK

ZOOM SIGNAL SWAP

REW FF SKIP

POWER

TIMER

FLASHBK

LIGHT

Illuminates the remote control buttons.

TV/VIDEO

Selects: DTV, Analog, Video1-2,

Component 1-2, RGB-DTV (or RGB-PC),

DVI-DTV (or DVI-PC) input sources.

COMP/RGB/DVI

Selects: Component 1-2, RGB-DTV (or RGB-

PC), DVI-DTV (or DVI-PC) input sources.

NUMBER buttons

DASH

Used to enter a program number for multiple

program channels such as 2—1,2—2,etc.

MUTE

Switches the sound on or off.

VCR/DVD BUTTONS

Control some video cassette recorders or
DVD player ("RECORD" button is not avail­able for DVD player).

RATIO

Changes the aspect ratio.

MODE

Selects the remote operating mode: TV,
VCR, DVD, CABLE, HDSTB or AUDIO.
Select other operating modes, for the
remote to operate external devices.

POWER

Turns your TV or any other programmed
equipment on or off, depending on mode.

TIMER

Lets you select the amount of time before
your TV turns itself off automatically.

SURF

Use to scroll the Surf channel list.

CC

Select a closed caption:
Off, EZ Mute, and On.

FLASHBK

Tunes to the last channel viewed.

THUMBSTICK (Up/Down/Left/Right/OK)

Allows you to navigate the on-screen

menus and adjust the system settings to

your preference.

CHANNEL UP/DOWN

Selects available channels found
with EZ scan.

EXIT

Clears all on-screen displays and returns to
TV viewing from any menu.

VIDEO

Adjusts the factory preset picture according
to the room.

VOLUME UP/DOWN

Increases/decreases the sound level.

SAP

Selects MTS sound: Mono, Stereo, and SAP.

Change the audio language in DTV mode.

MENU

Brings up the main menu to the screen.

INFO

When you watch the TV, displays information

on top of the screen. Not available in

Component 1-2, RGB and DVI mode.

SOUND

Selects the sound appropriate

for the program's character.

PIP

Switches between PIP, POP (Picture-out-of­Picture) and Twin picture modes.

PIPCH-/PIPCH+

Changes to next higher/lower PIP channel.

PIP INPUT

Selects the input source for the sub picture.

SWAP

Exchanges the PIP/main images.

FREEZE

Freezes the currently-viewed picture. Main

picture is frozen in PIP/Twin picturre mode.

ADJUST

Adjusts screen position, clock, and

phase in PC mode.

ZOOM

Enlarges the main picture size.

SIGNAL

Displays the digital signal strength.

Remote Control Key Functions

Remote Control Key Functions

DESCRIPTION OF CONTROLS

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ADJUSTMENT INSTRUCTIONS

1. Application Object

These instructions are applied to all of the PDP TV, AF-044A.

2. Notes

(1) Because this is not a hot chassis, it is not necessary to use

an isolation transformer. However, the use of isolation

transformer will help protect test instrument.
(2) Adjustments must be done in the correct order.
(3) The adjustments must be performed in the circumstance of

25±5°C of temperature and 65±10% of relative humidity if

there is no specific designation.
(4) The input voltage of the receiver be must kept 100~240V,

50/60Hz when adjusting.
(5) The receiver must be operational for about 15 minutes

prior to the adjustments.

1) After receiving 100% white pattern, the receiver must be
operated prior to adjustment. (Or 7. White Pattern
condition in EZ - Adjust)

2) Enter into White Pattern

- Enter the Ez - Adjust by pressing ADJ Key on Service

Remote Control (S R/C).

- Select the 7. White Pattern using CH +/- Key and

press the Enter(

Y) Key.

Display the 100% Full White Pattern.

[ Set is activated HEAT-RUN without signal generator in

this mode.

If you turn on a still screen more than 20 minutes (Especially
Digital pattern(13 CH), Cross Hatch Pattern), an afterimage
may occur in the black level part of the screen.

3. EPLD Download

(1) Test Equipment: PC, Jig for download
(2) Connect the power of VSC B/D.
(3) Execute download program(Flash Loader) of PC.
(4) After executing execution hot key (Programmer), icon click
(5) End after confirming

Each PCB Assy must be checked by Check JIG Set before
assembly. (Especially, be careful Power PCB Assy which can
cause fatal Damage to PDP Module.)

4. POWER PCB Assy Voltage
Adjustment

(Va, Vs Voltage Adjustment)

4-1 Test Equipment :D.M.M 1EA
4-2 Connection Diagram for Measuring

Refer to Fig 2.

PC

VSC

B/D

<Fig 1> Connection Diagram of EPLD Download

<Fig 2-1> Connection Diagram of Power Adjustment for

Measuring (Power Board): 42PY10 Series

<Fig 2-2> Connection Diagram of Power Adjustment for

Measuring (Power Board): 50PY10 Series