LG 42PQ30 Service Manual

Training Manual

PRELIMINARY

Advanced Single Scan Troubleshooting

42PQ30 Plasma Display

720p

NOTICE: ALL INFORMATION CONTAINED WITHIN THIS PACKAGE IS BASED ON PRE-SALES MODEL. INFORMATION SUBJECT TO CHANGE AT FINAL PRODUCTION

OUTLINE

Section 1

Section 2

Overview of Topics to be Discussed

Contact Information, Preliminary Matters, Specifications, Plasma Overview, General Troubleshooting Steps, Disassembly Instructions, Voltage and Signal Distribution

Circuit Board Operation, Troubleshooting and Alignment of :

• Switch mode Power Supply

• Y SUS Board

NEW

• Y Drive Boards (Receives Y Drive signals from Y-SUS PWB)

• Z SUS Output Board (Connects directly with FPC to Panel)

• Control Board

• X Drive Boards (2)

• Main Board

• Main Power Switch, deactivates all inputs from IR or Keys

Preliminary Information 42PQ30

Overview of Topics to be Discussed

42PQ30 Plasma Display

Section 1

This Section will cover Contact Information and remind the Technician of Important Safety Precautions for the Customers Safety as well as the Technician and the Equipment.

Basic Troubleshooting Techniques which can save time and money sometimes can be overlooked. These techniques will also be presented.

This Section will get the Technician familiar with the Disassembly, Identification and Layout of the Plasma Display Panel.

At the end of this Section the Technician should be able to Identify the Circuit Boards and have the ability and knowledge necessary to safely remove and replace any Circuit Board or Assembly.

Preliminary Information 42PQ30

Preliminary Matters (The Fine Print)

IMPORTANT SAFETY NOTICE

The information in this training manual is intended for use by persons possessing an adequate background in electrical equipment, electronic devices, and mechanical systems. In any attempt to repair a major Product, personal injury and property damage can result. The manufacturer or seller maintains no liability for the interpretation of this information, nor can it assume any liability in conjunction with its use. 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. If wires, screws, clips, straps, nuts, or washers used to complete a ground path are removed for service, they must be returned to their original positions and properly fastened.

CAUTION

To avoid personal injury, disconnect the power before servicing this product. If electrical power is required for diagnosis or test purposes, disconnect the power immediately after performing the necessary checks. Also be aware that many household products present a weight hazard. At least two people should be involved in the installation or servicing of such devices. Failure to consider the weight of an product could result in physical injury.

Preliminary Information 42PQ30

(Electrostatic Static Discharge)

ESD NOTICE

Today’s sophisticated electronics are electrostatic discharge (ESD) sensitive. ESD can weaken or damage the electronics in a manner that renders them inoperative or reduces the time until their next failure. Connect an ESD wrist strap to a ground connection point or unpainted metal in the product. Alternatively, you can touch your finger repeatedly to a ground connection point or unpainted metal in the product. Before removing a replacement part from its package, touch the anti-static bag to a ground connection point or unpainted metal in the product. Handle the electronic control repackaging a failed electronic control assembly in an anti-static bag, observe these same precautions.

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 the receiver; Connect the equipment to an outlet on a different circuit than that to which the receiver is connected; or consult the dealer or an experienced radio/TV technician for help.

(Electrostatic Static Discharge)

assembly by its edges only. When

Preliminary Information 42PQ30

CONTACT INFORMATION

Customer Service (and Part Sales) (800) 243-0000

Technical Support (and Part Sales) (800) 847-7597

USA Website (GCSC) aic.lgservice.com Customer Service Website us.lgservice.com

LG CS Academy lgcsacademy.com

LG Web Training lge.webex.com

Published March 2009 by LG Technical Support and Training

LG Electronics Alabama, Inc.

201 James Record Road,

Huntsville, AL, 35813.

Preliminary Information 42PQ30

SECTION 1:

Safety & Handling Regulations

1. Approximately 10 minute pre-run time is required before any adjustments are performed.

2. Refer to the Voltage Sticker inside the Panel when making adjustments on the Power Supply, Y SUS and Z SUS Boards. Always adjust to the specified voltage level (+/- ½ volt).

3. Be cautious of electric shock from the PDP module since the PDP module uses high voltage, check that the Power Supply and Drive Circuits are completely discharged because of residual current stored before Circuit Board removal.

4. C-MOS circuits are used extensively for processing the Drive Signals and should be protected from static electricity.

5. The PDP Module must be carried by two people. Always carry vertical NOT horizontal.

6. The Plasma television should be transported vertical NOT horizontal.

7. Exercise care when making voltage and waveform checks to prevent costly short circuits from damaging the unit.

8. Be cautious of lost screws and other metal objects to prevent a possible short in the circuitry.

9. New Panels and Frames are much thinner than previous models. Be Careful with flexing these panels. Be

careful with lifting Panels from a horizontal position. Damage to the Frame mounts or panel can occur.

PLASMA OVERVIEW

10. New Plasma models have much thinner cabinet assemblies and mounts. Be extremely careful when moving

the set around as damage can occur.

Checking Points to be Considered

1. Check the appearance of the Replacement Panel and Circuit Boards for both physical damage and part number accuracy.

2. Check the model label. Verify model names and board model matches.

3. Check details of defective condition and history. Example: Y Board Failure, Mal-discharge on screen, etc.

Preliminary Information 42PQ30

Basic Troubleshooting Steps

Define, Localize, Isolate and Correct

•Define the failure. Use your senses Sight, Smell, Touch and Hearing. Look for burned parts and check for possible overheated components. Capacitors will sometimes leak dielectric material and give off a distinct odor. Frequency of power supplies will change with the load, or listen for relay closing etc. Observation of the front Power LED may give some clues.

•Localize checked and after giving a thorough examination using your senses the first check should always be the DC Supply Voltages to those circuits under test. Always confirm the supplies are not only the proper level but be sure they are noise free. If the supplies are missing check the resistance for possible short circuits.

•Isolate Oscilloscope to make a final determination of the failure. Look for correct Amplitude Phasing and Timing of the signals also check for the proper Duty Cycle of the signals. Sometimes “glitches” or “road bumps” will be an indication of an imminent failure.

Look at the symptom carefully and determine what circuits could be causing

After carefully checking the symptom and determining the circuits to be

To further isolate the failure, check for the proper waveforms with the

•Correct check the DC Supplies for proper levels. Make all necessary adjustments and lastly always perform a Safety AC Leakage Test before returning the product back to the Customer.

The final step is to correct the problem. Be careful of ESD and make sure to

Preliminary Information 42PQ30

42PQ30 Product Information

This section of the manual will discuss the specifications of the 42PQ30 Advanced Single Scan Plasma Display Panel.

Preliminary Information 42PQ30

42PQ30 Specifications

42” Class (41.5” diagonal)

• 720p HD Resolution

• Dual XD Engine™

• 20,000:1 Contrast Ratio

• Fluid Motion

• 3x HDMI™ V.1.3 with Deep Color

• AV Mode (Cinema, Sports, Game)

720P PLASMA HDTV

• Clear Voice

• LG SimpLink™ Connectivity

• Invisible Speaker System

• 100,000 Hours to Half Brightness (Typical)

• PC Input

Preliminary Information 42PQ30

42PQ30 Specifications Logo Familiarization

HD RESOLUTION 720p HD Resolution Pixels: 1365 (H) × 768 (V) High definition television is the highest performance segment of the DTV system used in the US. It’s a wide screen, high-resolution video image, coupled with multi-channel, compact-disc quality sound.

HDMI (1.3 Deep Color) Digital multi-connectivity

HDMI (1.3 Deep color) provides a wider bandwidth (340MHz,

10.2Gbps) than that of HDMI 1.2, delivering a broader range of colors, and also drastically improves the data-transmission speed.

Invisible Speaker Personally tuned by Mr. Mark Levinson for LG

TAKE IT TO THE EDGE newly introduces ‘Invisible Speaker’ system, guaranteeing first class audio quality personally tuned by Mr. Mark Levinson, world renowned as an audio authority. It provides Full Sweet Spot and realistic sound equal to that of theaters with its Invisible Speaker.

1024 (H) × 768 (V) Actual Pin Count

Dual XD Engine Realizing optimal quality for all images

One XD Engine optimizes the images from RF signals as another XD Engine optimizes them from External inputs. Dual XD Engine presents images with optimal quality two times higher than those of previous models.

Preliminary Information 42PQ30

42PQ30 Specifications Logo Familiarization

AV Mode "One click" - Cinema, Sports, Game mode.

TAKE IT TO THE EDGE is a true multimedia TV with an AV Mode which allows you to choose from 3 different modes of Cinema, Sports and Game by a single click of a remote control.

Clear Voice Clearer dialogue sound

Automatically enhances and amplifies the sound of the human voice frequency range to provide high-quality dialogue when background noise swells.

Save Energy, Save Money

It reduces the plasma display’s power consumption. The default factory setting complies with the Energy Star requirements and is adjusted to the comfortable level to be viewed at home. (Turns on Intelligent Sensor).

Save Energy, Save Money

Home electronic products use energy when they're off to power features like clock displays and remote controls. Those that have earned the ENERGY STAR use as much as 60% less energy to perform these functions, while providing the same performance at the same price as less-efficient models. Less energy means you pay less on your energy bill. Draws less than 1 Watt in stand by.

Preliminary Information 42PQ30

42PQ30 Specifications

FluidMotion

Familiarization

FluidMotion (180 Hz Effect)

Enjoy smoother, clearer motion with all types of programming such as sports and action movies. The moving picture resolution give the impression of performance of up to 3x the panels actual refresh rate.

LCD 60Hz

Moving Picture Response Time

is 16.5 milliseconds

(120Hz takes MPRT to 8.25ms)

Panel Response Time

is 4 to 8 milliseconds

PDP

180Hz

Moving Picture Response Time

is 5.44 milliseconds

Panel Response Time

is less than 1 millisecond

Preliminary Information 42PQ30

42PQ30 Remote Control

TOP PORTION

BOTTOM PORTION

Preliminary Information 42PQ30

Rear and Side Input Jacks

AC In

USB

Software

Upgrades

Preliminary Information 42PQ30

42PQ30 Product Dimensions

Wattage

Avg: 181W

Stby: 0.13W

28-5/16"

718.8mm

25-13/16"

655.3mm

There must be at least 4 inches of Clearance on all sides

40-1/2"

1028.7mm

15-3/4"

12-3/16"

310mm

15-3/4"

400mm

15-3/4"

400mm

Center

12-13/16"

325mm

3-1/8"

78.7mm

4-1/8"

104mm

Model No.

Serial No.

Label

2-9/16"

65mm

Weight without Stand: 50 lb Weight with Stand: 54.7 lb

5-13/16"

148mm

23-5/8"

600mm

Remove 4 screws to

remove stand for

wall mount

12-1/8"

307.3mm

DISASSEMBLY SECTION

This section of the manual will discuss Disassembly, Layout and Circuit Board Identification, of the 42PQ30 Advanced Single Scan Plasma Display Panel.

Upon completion of this section the Technician will have a better understanding of the disassembly procedures, the layout of the printed circuit boards and be able to identify each board.

Preliminary Information 42PQ30

42PQ30 Removing the Back Cover

To remove the back cover, remove the 26 screws

(The Stand does not need to be removed).

Indicated by the arrows.

PAY CLOSE ATTENTION TO THE TYPE, SIZE AND LENGTH

Of the screws when replacing the back cover.

Improper type can damage the front.

Preliminary Information 42PQ30

42PQ30 Circuit Board Layout

Y Drive

FPC

Panel Voltage Label

Y SUS PWB

Power Supply (SMPS) PWB

Panel ID Label

FPC

Z-SUS PWB

FPC

Side Input

(part of main)

FPC

Master

Power

TCP

Heat Sink

Left “X”

Control Keys

Control PWB

Invisible Speakers

Main PWB

AC In

Right “X”

Conductive Tape Under Main PWB

Preliminary Information 42PQ30

Disassembly Procedure for Circuit Board Removal

Notes: 1) All Plugs listed are from left to right Pin 1,2, 3, ETC.

2) Remember to be cautious of ESD as some semiconductors are CMOS and prone to static failure

Switch Mode Power Supply Board Removal

Disconnect the following connectors: P811, P813, SC101 Remove the 8 screws holding the PWB in place Remove the PWB When replacing, be sure to readjust the Va/Vs voltages in accordance with the Panel Label. Confirm VSC, -Vy and ZBias as well.

Y-SUS Board Removal

Disconnect the following connectors: P201, P206, P101, P202 Remove the 7 screws holding the PWB in place Remove the PWB by lifting slightly and sliding it to the right. When replacing, be sure to readjust the Va/Vs voltages in accordance with the Panel Label. Confirm VSC, -Vy and Zbias as well.

Y Drive Board Removal

Disconnect the following Flexible Ribbon Connectors: P1, P2, P3, P4, P5, P6, P7 and P8 Disconnect the following connectors: P201, P801, P101, P202 Remove the 3 screws holding the PWB in place Remove the PWB by lifting slightly and sliding the PWB to the left unseating P204 and P200 from the Y-SUS PWB. Note: PWB stand-offs have a small collar. The board must be lifted slightly to clear these collars.

Preliminary Information 42PQ30

Disassembly Procedure for Circuit Board Removal (2)

Z-SUS Board Removal

Disconnect the following connectors: P3, P2. Disconnect the following connectors: P6 and P7. These are the FPC cables. Pull the locking caps to the right. Lift carefully the Flexible Printed Circuits (FPCs) and slide them out to the right. Remove the 5 screws holding the PWB in place Lift the PWB up and remove the PWB. When replacing, be sure to readjust the Va/Vs voltages in accordance with the Panel Label. Confirm VS, -Vy and Zbias as well.

Main Board Removal

Disconnect the following connectors: P301, P1001, P1002 and P1005 Remove the 1screws holding on the decorative plastic piece on the right side Remove the 4 screws holding the PWB in place and Remove the PWB.

Control Board Removal

Disconnect the following connectors: P121 LVDS, P101, P111 Ribbon, P161 Ribbon and P162 Ribbon. Remove the 4 screws holding the PWB in place Remove the PWB.

Front Key and LED PWB Removal

Remove the 2 screws holding the Key PWB in place. Remove the PWB. Disconnect P101, (Note: LED PWB is behind the Key PWB. Remove it’s 2 screws and remove. Disconnect J1 and J2.

X-Drive Boards Removal

Disconnect the following connectors: P232, P211, P311 and P331 Remove the 6 screws holding the Heat Sink in place. Rock back and slide down to remove. Disconnect the following connectors: P201 through P206 and P301 through P306 Remove the 3 screws holding each of the X Drive PWBs in place (8 total) Remove the PWBs.

Preliminary Information 42PQ30

X Drive Circuit Board Removal Continued

Lay the Plasma down carefully on a padded surface. Make sure AC is removed and remove the Back Cover and the Stand. Carefully remove the LVDS Cable P121 from the Control Board by pressing the Locking Tabs together and Pull the connector straight back to remove the cable see illustration below. (This prevents possible damage).

Press

Inward

LVDS Cable Connector

(A) Remove the Stand mount (4 Screws removed during back removal). (B) Remove the Stand Metal Support Bracket (4 Screws). (C) Remove connector P1001 and P1005. (D) Remove the 4 screws from the Main Board Mounting Bracket. (Note: Decorative Plastic Piece on right does not need to

be removed)

Carefully reposition the Main Board and Mounting Bracket up and off to the right side. (E) Remove the metal support Br aces marked “E”. Note: There is a Left and a Right brace. (3 Screws per/bracket). (F) Remove the 13 screws holding the Heat Sink.

X-DRIVE PWBs REMOVAL:

Disconnect all TCP ribbon cables from the defective X-Drive PWB. Remove the 4 screws holding the PWB in place. Remove the PWB. Reassemble in reverse order. Recheck Va / Vs / VScan / -VY / Z-Drive.

Press

Inward

Preliminary Information 42PQ30

Getting to the X Circuit Boards

Warning: Never run the TV with the TCP Heat Sink removed

Heat Sink

Left

Warning Shorting Hazard: Conductive Tape. Do not allow to touch energized circuits.

Right

Preliminary Information 42PQ30

Left and Right X Drive Removal

After removing the back cover, Main PWB is lifted out of the way, 6 screws removed from heat sink covering heat sink and TCPs removed, the X-Drive PWBs can be removed.

Showing the tape on the connectors P232 or P331

Peel the tape off the connectors Gently pry the locking mechanism upward and remove the ribbon cable from the connector.

Removing TCPs.

Gently lift the locking mechanism upward on all

TCP connectors P201~206 or P301~306

Cushion (Chocolate)

Flexible ribbon cable

TCP

Carefully lift the TCP ribbon up and off.

Preliminary Information 42PQ30

TCP (Tape

Note: These picture are taken from a different model. But the precautions are the same.

Carrier

Package) Generic Removal Precautions

TCP Connector Removal

Lift up the lock as shown by arrows.

(The Lock can be easily broken.

It needs to be handled carefully.)

Pull TCP apart as shown by arrow.

(TCP Film can be easily damaged. Handle with care.)

Preliminary Information 42PQ30

Left and Right X Drive Removal

Remove the 4 screws for either PWB or 7 total for both. (The Center screw secures both PWBs)

Left X Board drives the right side of the screen

Right X Board drive the left side of the screen

Preliminary Information 42PQ30

SECTION 2: CIRCUIT OPERATION, TROUBLESHOOTING AND

CIRCUIT ALIGNMENT SECTION

42PQ30 Plasma Display

This Section will cover Circuit Operation, Troubleshooting and Alignment of the Power Supply, Y-SUS Board, Y Drive Boards, Z-SUS Board, Control Board, Main Board and the X Drive Boards.

At the end of this Section the technician should understand the operation of each circuit board and how to adjust the controls. The technician should be able with confidence to troubleshoot a circuit board failure, replace the defective circuit and perform all necessary adjustments.

Preliminary Information 42PQ30

Y Drive PWB

FPCs

42PQ30 SIGNAL and VOLTAGE DISTRIBUTION BLOCK DIAGRAM

Display Panel

Horizontal Address Reset

P201

P202

Floating

Ground

P203

P204

P205

P101

P103

P102

V Scan

P104

Floating

Drive Data

P206

Clock (i2c)

Display Panel

Horizontal Address

Y-SUS

PWB

P203

P208

P205

P207

P202

P201

P206

P101

M5V, Vs, Va

Logic Signals

5V / 17V

P811

SN101

P160

CONTROL

P161

RGB Logic

Signals

3.3V 3.3V

P232

SMPS

PWB

P813

AC Input Filter

P121

PWB

P101

P162

RGB Logic

Signals

P211 P311 P331

SMPS OUTPUT VOLTAGES IN STBY

STB +5V (AC Voltage Det)

SMPS OUTPUT VOLTAGES IN RUN

STB +5V, 17V, 12V to Main PWB Vs, Va and M5V to Y-SUS

SMPS

Turn On

Commands

Set Off: STB +5

AC Voltage Det

STBY

Relay On M5 On VS On

X-PWB-RightX-PWB-Left

Vs and

Er Com

LVDS

P301

P1002

MAIN PWB

P1001

IR, Power LED,

Intelligent Sensor

Z SUS

PWB

5V / 17V

Z Drive Signals

Speakers

Control Keys

Master Power Switch

FPCs

P201 P202 P203 P204 P205 P206 P301 P302 P303 P304 P305 P306

Display Panel Vertical Address

Panel Label Explanation

(9) (10)

(1)

(8)

(2) (3)

(4) (5)

(6) (7)

(1) Model Name (2) Bar Code (3) Manufacture No. (4) Adjusting Voltage DC, Va, Vs (5) Adjusting Voltage (Set Up / -Vy / Vsc / Ve / Vzb) (6) Trade name of LG Electronics

(11)

(12)

(13) (14) (15)

(9) TUV Approval Mark (10) UL Approval Mark (11) UL Approval No. (12) Model Name (13) Max. Watt (Full White)

(14) Max. Volts (7) Manufactured date (Year & Month) (8) Warning

(15) Max. Amps

Preliminary Information 42PQ20

ADJUSTMENT NOTICE

It is critical that the DC Voltage adjustments be checked when;

1) SMPS, Y-SUS or Z-SUS PWB is replaced.

2) Panel is replaced, Check Va/Vs since the SMPS does not come with new panel

3) A Picture issue is encountered

4) As a general rule of thumb when ever the back is removed

ADJUSTMENT ORDER “IMPORTANT” DC VOLTAGE ADJUSTMENTS

1) SMPS PWB: Va Vs (Always do SMPS first)

2) Y-SUS PWB: Adjust –Vy, Vscan,

3) Z-SUS PWB: Adjust ZBias WAVEFORM ADJUSTMENTS

1) Y-SUS PWB: Set-Up, Set-Down

Remember, the Voltage Label MUST be followed,

it is specific to the panel’s needs.

Manufacturer

Bar Code

The Waveform adjustment is only necessary

1) When the Y-SUS PWB is replaced

2) When a “Mal-Discharge” problem is encountered

3) When an abnormal picture issues is encountered

Set-

-VY

Vscan

All label references are from a specific panel.

They are not the same for every panel encountered.

Z_BIAS

Preliminary Information 42PQ30

Panel

“Rear View”

+ 94 hidden pages