50PC51.pdf

Internal Use Only

website:http://biz.LGservice.com

PLASMA TV

SERVICE MANUAL

CHASSIS : PP78A

MODEL : 50PC51 50PC51-ZB

CAUTION

BEFORE SERVICING THE CHASSIS,

READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

CONTENTS

CONTENTS ..............................................................................................2

SAFETY PRECAUTIONS..........................................................................3

SPECIFICATION........................................................................................4

ADJUSTMENT INSTRUCTION.................................................................6

TROUBLESHOOTING............................................................................15

BLOCK DIAGRAM...................................................................................23

EXPLODED VIEW ..................................................................................24

EXPLODED VIEW PARTS LIST ............................................................25

REPLACEMENT PARTS LIST...............................................................26

SVC. SHEET ...............................................................................................

PRINTED CIRCUIT DIAGRAM....................................................................

Only for training and service purposes

- 2 -

LGE Internal Use Only

SAFETY PRECAUTIONS

IMPORTANT SAFETY NOTICE

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

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 exposed 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 specified, there is

possibility of shock hazard and the set must be checked and

repaired before it is returned to the customer.

An isolation 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 circuitry that may be

inadvertently introduced during the service operation.

If any fuse (or Fusible Resistor) in this monitor is blown, replace it

with the specified.

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 Hot Check circuit

Due to high vacuum and large surface area of picture tube,

extreme care should be used in handling the Picture Tube.

Do not lift the Picture tube by it's Neck.

AC Volt-meter

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.

An other abnormality exists that must be corrected before the

receiver is returned to the customer.

To Instrument's

exposed

METALLIC PARTS

0.15uF

Good Earth Ground

such as WATER PIPE,

CONDUIT etc.

1.5 Kohm/10W

Only for training and service purposes

- 3 -

LGE Internal Use Only

SPECIFICATIONS

NOTE : Specifications and others are subject to change without notice for improvement.

V Application Range

This spec is applied to the 50” PLASMA TV used PP78A Chassis.

Chassis

PP78A

Model Name

Market

Brand

Remark

50PC51-ZB

V Specification

Each part is tested as below without special appointment.

1) Temperature : 25±5°C (77±9°F), CST : 40±5

2) Relative Humidity: 65±10%

3) Power Voltage: Standard Input voltage (100-240V~, 50/60Hz)

* Standard Voltage of each product is marked by models.

4) Specification and performance of each parts are followed each drawing and specification by part number in accordance with SBOM.

5) The receiver must be operated for about 20 minutes prior to the adjustment.

V Test Method

1) Performance : LGE TV test method followed.

2) Demanded other specification

Safety : CE, IEC specification

EMC : CE, IEC

Model

Market

Appliance

Remark

50PC51-ZB

Safety : IEC/EN60065, EMI : EN55013, EMS : EN55020

TEST

V General Specification ( 50”XGA )

Item

Specification

Remark

Display Screen Device

50” Wide Color Display Module

Plasma Display Panel

Aspect Ratio

16:9

PDP Module

PDP50X4A(P),

Glass Filter

RGB Closed Type

Operating Environment

1)Temp. : 0~40deg

LGE SPEC.

2)Humidity : 0~85%

Storage Environment

3)Temp. : -20~60deg

4)Humidity : 0~85%

Input Voltage

100-240V~, 50/60Hz

Maker : Sanken

Only for training and service purposes

- 4 -

LGE Internal Use Only

V Module Specification

Item

Specification

Remark

Market

Broadcasting system

PAL-BG/I/DK, NTSC, SECAM

Available Channel

BAND

PAL

VHF/UHF

C1~C69

CATV

S1~S47

Receiving system

Upper Heterodyne

SCART Jack(2EA)

PAL, SECAM, NTSC

FULL SCART, HALF SCART

Video Input (1EA)

PAL, SECAM, NTSC

SIDE AV

S-Video Input (1EA)

PAL, SECAM, NTSC

SIDE S-VIDEO

Component Input (1EA)

Y/Cb/Cr, Y/Pb/Pr

RGB Input(1EA)

RGB-PC

HDMI Input(1EA)

HDMI-DTV

Audio Input (5EA)

PC Audio, Component(1EA),

L/R Input

AV (2EA), SIDE AV(1EA)

Audio variable out(1EA)

Only for training and service purposes

- 5 -

LGE Internal Use Only

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