LG 42PC51, 42PC51-ZB Service Manual

PLASMA TV

SERVICE MANUAL

CAUTION

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

CHASSIS : PP78A

MODEL : 42PC51 42PC51-ZB

website:http://biz.LGservice.com

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CONTENTS

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

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

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

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

TROUBLE SHOOTING ............................................................................16

BLOCK DIAGRAM...................................................................................24

EXPLODED VIEW .................................................................................. 26

EXPLODED VIEW PARTS LIST ............................................................ 27

REPLACEMENT PARTS LIST ............................................................... 28

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

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

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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 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.

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.

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.

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.

Leakage Current Hot Check circuit

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

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

V Application Range

This spec is applied to the 42” PLASMA TV used PP78A Chassis.

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

V General Specification ( 42”XGA Module with 40%)

Display Screen Device

Aspect Ratio

PDP Module

Operating Environment

Storage Environment

Input Voltage

No Item Specification Remark

42” Wide Color Display Module

16:9

PDP42X4,

RGB Closed Type

1)Temp. : 0~40deg

2)Humidity : 0~85%

3)Temp. : -20~60deg

4)Humidity : 0~85%

100-240V~, 50/60Hz

Plasma Display Panel

Clear Filter

LGE SPEC.

Maker : LG

Chassis

PP78A 42PC51-ZB EU LG

Model Name Market Brand Remark

42PC51-ZB Safety : IEC/EN60065, EMI : EN55013, EMS : EN55020EU

Model ApplianceMarket

TEST

Remark

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V Module Specification1 (PDP42X4)

Display area

Outline dimension

Number of Pixels

Cell pitch

Color arrangement

Weight(net)

Weight(gross)

Item

Temperature

Operating Environment Humidity

Pressure

Temperature

Storage Environment Humidity

Pressure

Image stick Start time

minimization Low Brightness Arrival Time

mode

921.5 (H) * 519.0(V)±0.5

1005 (W) x 597 (H) x 60.7 (D)±1

1024 (H) x 768(V)

300um (H) x 676um (V)

RGB closed type

13.8 14.3 14.8

192.5 197.5 202.5

Min Typ Max

0 ~ 40

20 ~ 80

800 ~ 1100

-20 ~ 60

10 ~ 90

700 ~ 1100

4.5 5 5.5

14 15 16

No Item Remark

1Pixel=3RGB Cells

5EA 1Box

Remark

Altitude : 0 to 2000M

Altitude : 0 to 3000M

Unit

deg

hPa

deg

hPa

min

Min Typ Max Unit

V Module Specification2

Market

Broadcasting system

Available Channel

Receiving system

SCART Jack(2EA)

Video Input (1EA)

S-Video Input (1EA)

Component Input (1EA)

RGB Input(1EA)

HDMI Input(1EA)

Audio Input (5EA)

Audio variable out(1EA)

No Item Specification Remark

PAL-BG/I/DK, NTSC, SECAM

BAND PAL

VHF/UHF C1~C69

CATV S1~S47

Upper Heterodyne

PAL, SECAM, NTSC

Y/Cb/Cr, Y/Pb/Pr

RGB-PC

HDMI-DTV

PC Audio, Component(1EA),

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

FULL SCART, HALF SCART

SIDE AV

SIDE S-VIDEO

L/R Input

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ADJUSTMENT INSTRUCTION

1. Application Object

These instructions are applied all of the 42” PLASMA TV,

PP78A Chassis.

2. Note

(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) Adjustment must be done in the correct order. (3) The adjustment 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 must keep 100-220V~,

50/60Hz. (5) Before adjustment, execute Heat Run for 30 minutes.

3. Adjustment items

3.1. PCB assembly adjustment items

(1) Download the VCTP main software (IC500,VCT_Pro) (2) Channel memory (IC501,EEPROM) (3) Color carrier Adjustment

3.2. SET assembly adjustment items

(1) DDC Data input. (2) Adjustment of White Balance. (3) Factoring Option Data input.

4. PCB assembly adjustment method

(Using VCTP Download program)

4-1. Download program installation

(1) Extract a Zip file.

(2) Visual I2C & LPT Driver Installation.

LPT Port Driver (LptDrv) Setups : Program Files > Micronas >

Visual I2C > Port_Driver *Use for Windows 95/98 : Setup_LptDrv_v0104_9x.exe *Use for Windows 2000/XP : Setup_LptDrv_v0202_XP_2000.exe *

Use for Windows NT : Setup_LptDrv_v0104_NT.exe

(3) Verification.(Start > Programs > Micronas > Visual I2C or

LptDrv)

(4) LPT delay setting.(File > Preference > LPT preferences)

(5) Exchange the “bootloader.bat” file.

Click the red area

Double click the Red

Install the LPT Driver Install the Visual I2C

*LPT SETTING

- Delay => 1

- Time out => 500 ms

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=> Select the "Bootloader.bat" file.

(install > VCTP_download > Bootloader)

=> Push "OK".

Finish the program, after saving the file "download_cs.vi2c".

(if you click , the massage appears automatically)

5. S/W program download

5-1. Profile

: This is for downloading the s/w to the flash memory of the

vctp(IC500)

5-2. Required Test Equipment

(1) PC. (2) Visual IIC program. (3) Download jig.

5-3. Connection structure

6. Download method

6-1. Download method 1 (PCB Ass’y)

(1) Connect the download jig to D-sub jack. (2) Execute ‘Download.vi2c’ program in PC, then a main

window will be opened.

(3)

Double click the blue box and confirm "Bootloader Version" as 42.

(4) Click the "Erase Flash" button.

(5) Double click the download file low, then "edit" window will

be opened.

(6) Click the choice button in the “edit window”, then “file

choice window” will be opened.

(7) Choose the Hex file in folder and execute downloading

with click " open" button.

You must verify the words of “0xfffff” in the black box of figure. (In case of H3 Service it is 0x7ffff : If you make H4 service after the H3 service, there could be some problem)

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(8) Click OK button at the "edit window". (9) Under Downloading process.

(10) If download is failed, for example "No acknowledge from

slave". Execute download again from(1).

6-2.Download method 2 (AV Plate Ass’y)

(1) Push S/W ‘ON" (connect SCL to GND using switch at Jig )

and connect the download jig to D-sub jack.

(2) Supply the power (Stand-by 5V) and wait for 3 seconds.

(3)

Push the S/W off.(Disconnect SCL to GND using switch at jig).

(4) Execute ‘Download.vi2c’ program in PC, then a main

widow will be opened.

(5)

Double click the blue box and confirm "Bootloader Version" as 42

(6) Click the "Erase Flash" button.

(7) Double click the download file low then, "edit" window will

be opened.

(8) Chick the choice button I n the "edit window", then "file

choice window’ will be opened.

(9) Click the “load > flash” button. (10) Choose the Hex file in folder and execute downloading

with click "open button".

Push S/W

You must verify the words of “0xfffff” in the black box(A) of figure. (In case of H3 Service it is 0x7ffff : If you make H4 service after the H3 service, there could be some problem)

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(11) Click OK button at the "edit window".

(12) Under Downloading progress.

(13) If download is failed, for example "No acknowledge from

slave", execute download again from (1).

6-3.Download method 3 (SET)

(1) Push the “Tilt” button in an Adjust Remocon Then the

PLASMA TV will change a “slave mode”.

(2) Connect Zig to TV using a D-sub cable.

(3) Execute ‘Download_CS.vi2c’ program in PC, then a main

widow will be opened.

(4) Click "GO" button.

If you don’t push the “go” , the Hex file would not be

downloaded although the download proceeds normally at first glance.

(5) Double click the blue box and confirm "Bootloader

Version" as 42.

(6) Click the "Erase Flash" button.

(7) Double click the download file low then, "edit" window will

be opened.

(8) Chick the choice button I n the "edit window", then "file

choice window’ will be opened.

(9) Click the “load > flash” button.

You must verify the words of “0xfffff” in the black box(A) of figure. (In case of H3 Service it is 0x7ffff : If you make H4 service after the H3 service, there could be some problem)

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(10) Choose the Hex file in folder and execute downloading

with click "open button".

(11) Click OK button at the "edit window".

(12) Under Downloading progress.

(13) If download is failed, for example "No acknowledge from

slave", execute download again from (1).

7. Channel memory download

7-1. Profile

: This is for downloading the s/w to the flash memory of the

vctp(IC500)

7-2. Required Test Equipment

(1) PC. (2) Visual IIC program. (3) Download jig.

7-3. Connection structure

(1) Connect the download jig to D-sub jack. (2) Execute ‘Channel.vi2c’ program in PC, then a main

window will be opened.

7-4. Connection condition

(1) IC name and circuit number : VCTP and IC500. (2) Use voltage : 3.3V. (3) SCL : 15pin. (4) SDA : 12pin. (5) Tact time : about 3seconds.

7-5. Download method

(1) Connect the download jig to D-sub jack. (2) ‘Execute ‘Channel vi2c’ program in PC, then a main

window will be opened.

(3) Push the button change and select the Channel memory

data.

(4) Check the communication is OK or not. => Push the Read area (Ackn. Check) and check Cyan area

is OK message.

(5) Push the Update NVM from File

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8. Tool Option Area Option Change

8-1. Profile

Must be changed the option value because being different with some setting value depend on module, inch and market.

8-2. Required Test Equipment

1) Adjustment remocon.

8-3. Adjustment method

Before PCB check, have to change the Tool option and Area option. Option values are below. (If on changed the option, the input menu can differ the model spec.) The input methods are same as other chassises.(Use adj Key on the Adjust Remocon)

* After done all adjustments, Press ADJ button and compare

Tool option and Area option value with its BOM, if it is correctly same then unplug the AC cable. If it is not same, then correct it same with BOM and unplug AC cable. For correct it to the model’s module from factory JIG model.

9. Color carrier Adjustment (Inspection process)

9-1. Profile

: To have the margin about the deviation of color carrier to

satisfy the spec.

9-2. Required Test Equipment

1) Adjustment remocon.

2) Pal RF signal.

9-3. Connection

: TV set should connected with the pal RF signal(EU 5CH).

9-4. Adjustment method

(1) tuning the RF signal

ZA/ZB, TA/TB : PAL Philips Pattern (with Color Bar)

(2) push the “adj” key in the adjustment remocon.

10. POWER PCB Assy Voltage Adjustments (Va, Vs Voltage adjustments)

10-1. Profile

: To supply the Va, Vs voltage that the module want.

10-2. Required Test Equipment

(1) Stick for adjustment. (2) DMM.

10-3. Connection structure

10-4. Connection Diagram for Measuring

: refer to (Fig. 1)

10-5. Adjustment Method

(1) Va Adjustment

1) After receiving 100% Full White Pattern, HEAT RUN.

2) Connect + terminal of D. M..M. to Va pin of P812, connect

-terminal to GND pin of P812.

After turning VR901,voltage of D.M.M adjustment as same as Va voltage which on label of panel right/top. (deviation;

0.5V)

(2) Vs Adjustment

1) Connect + terminal of D. M..M. to Vs pin of P812, connect

-terminal to GND pin of P812.

After turning VR951, voltage of D.M.M adjustment as same as Vs voltage which on label of panel right/top. (deviation ;

±0.5V)

(Fig. 1)

Connection Diagram of power adjustment for measuring.

Each PCB assembly must be checked by check JIG set. (Because power PCB Assembly damages to PDP Module, especially be careful)

VGA

XGA

PC5R(PC51)

PC6R

PC7R

PB3R

PC5R(PC51)

PC6R

PC7R

PB3R

TOOL OPTION ZA/ZB TA/TB

2244

2500

2756

3012

2252

2508

2764

3020

4292

4548

4804

5060

4300

4556

4814

5068

11. EDID

(The Extended Display Identification Data )

/DDC(Display Data Channel) download

11-1. Profile

: To be possible for plug and play.

11-2. Required Test Equipment

(1) Adjusting PC with S/W for writing EDID Data.

(S/W : EDID TESTER Ver.2.5) (2) A Jig for EDID Download. (3) Cable : Serial(9Pin or USB) to D-sub 15Pin cable, D-sub

15Pin cable, DVI to HDMI cable.

11-3. Connection structure

* Caution

- Never connect HDMI & D-SUB Cable at the same time.

- Use the proper cables below for EDID Writing.

11-4. Preparation for Adjustment

(1) As above (Fig. 2), Connect the Set, EDID Download Jig,

PC & Cable. (2) Turn on the PC & EDID Download Jig. And Execute the

S/W : EDID TESTER Ver 2.5. (3) Set up S/W option.

Repeat Number : 5

Device Address : A0

PageByte : 8

(4) Power on the Set.

11-5. Sequence of Adjustment

(1) DDC data of Analog-RGB

1) Init the data.

2) Load the EDID data.(Open File).

[ Analog

RGB

: PP78A_RGB.ANA ]

[ Digital-HDMI1 :

PP78A_HDMI1.DVI ]

[ Digital-HDMI2 :

PP78A_HDMI2.DVI ]

3) Set the S/W as below.

(4) Push the “Write Data & Verify”button. And confirm “Yes”.

(5) If the writing is finished, you will see the “OK” message.

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For RGB EDID For HDMI EDID

(Fig. 2) Connection Diagram of DDC download

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