LG 42PQ30 Service Manual

Download

Page 1

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

Page 2

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

Page 3

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

Page 4

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

Page 5

(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

Page 6

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

Page 7

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

Page 8

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

Page 9

42PQ30 Product Information

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

Preliminary Information 42PQ30

Page 10

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

Page 11

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

Page 12

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

Page 13

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

Page 14

42PQ30 Remote Control

TOP PORTION

BOTTOM PORTION

Preliminary Information 42PQ30

Page 15

Rear and Side Input Jacks

AC In

USB

Software

Upgrades

Preliminary Information 42PQ30

Page 16

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

Page 17

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

Page 18

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

Page 19

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

Page 20

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

Page 21

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

Page 22

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

Page 23

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

Page 24

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

Page 25

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

Page 26

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

Page 27

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

Page 28

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

Page 29

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

Page 30

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”

Page 31

SWITCH MODE POWER SUPPLY Troubleshooting

This Section of the Presentation will cover troubleshooting the Switch Mode Power Supply for

the Single Scan Plasma. Upon completion of the section the technician will have a better understanding of the operation of the Power Supply Circuit and will be able to locate voltage and test points needed for troubleshooting and alignments.

• DC Voltages developed on the SMPS

• Adjustments VA and VS.

• Always refer to the Voltage Sticker located on the back of the panel, in the upper Left Hand side for the correct voltage levels for the VA, VS, -VY, Vscan, and Z Bias as these voltages will vary from Panel to Panel even in the same size category.

• Set-Up and Ve are just for Label location identification and are not adjusted in this panel.

Preliminary Information 42PQ30

Page 32

Switch Mode Power Supply Part Number

SMPS P/N EAY58349601 Check the silk screen label on the top center of the PWB of

the Power Supply itself to identify the PWB P/N. We will examine the Operation of this Power Supply.

Preliminary Information 42PQ30

Page 33

42PQ30 SMPS PWB LAYOUT (POWER SUPPLY)

P811

M5V M5V

Gnd

VA Gnd Gnd

N/C

Hot Ground: Represents a Shock Hazard

P811

L602

L601

Both F801

and F302 read from

Hot Gnd

F801

4A/250V

Primary Bridge Rectifier

Stby 338V

Run 388V

Hot Ground

F302

Hot Ground

RL101

1A/250V

Stby 338V

Run 388V

RL103

8A/250V

T901

VR901

T301

VR502

IC701

17V

Gnd

12V

Gnd

5V Det

RL ON

M5 ON

Stby5V

P813

17V

Gnd

12V

Gnd

N/C

AC Det

VS ON

Auto Gnd

Key On

101

SC101

AC In

P813

Page 34

Switch Mode Power Supply Overview

The Switch Mode Power Supply Board Outputs to the :

Y-SUS Board

Main Board

M5V VCC

16V Audio B+ Supply

5V Signal Processing Circuits

There are 2 adjustments located on the Power Supply Board VA and VS. The 5V VCC is pre-adjusted and fixed. All adjustments are made with relation to Chassis Ground. Use “Full White Raster” 100 IRE

Drives the Display Panel Horizontal Grid

Primarily responsible for Display Panel Vertical Grid

Used to develop Bias Voltages on the Y-SUS, X Drive, and Control Boards

Adjustments

RV901

RV951

Preliminary Information 42PQ30

Page 35

Switch Mode Power Supply Circuit Layout

P811

To Y-SUS

PFC

Main Bridge Rectifier

Circuit

380V

Source

338V Stby

388V Run

Fuse F801

4Amp/250V

338V Stby

388V Run

Fuse F302

1Amp/250V

VS VR901

VA Source

VS Source

STBY 5V 17V, 12V

VA VR502

IC701

Sub Micon

Main Fuse

F101

6.3Amp/250V

Source

AC Input

SC 101

P813

To MAIN

Preliminary Information 42PQ30

Page 36

Power Supply Basic Operation

AC Voltage is supplied to the SMPS Board at Connector SC101 from the AC Input Filter. Standby 5V is developed from 90V source supply (which during run measures 359V). This supply is also used to generate all other voltages on the SMPS.

The 5V (standby) voltage is routed to the Sub Micon circuit (IC701) on the SMPS and through P813 to the Main PWB for Micon (IC1) operation. AC detect Pin 18, P813 is generated on the SMPS by monitoring the AC input and rectifying a small sample voltage. This AC Detect Voltage is routed to (IC701) the Sub Micon on the SMPS and through pin 18 of PG813 to the Micon (IC1) located on the Main Board and is used to Reset the Main Board.

When the Micon (IC1) on the Main Board receives an “ ON “ Command from either the Keyboard or the Remote IR Signal it outputs a high called RL ON. This signal first turns on a DC level shifter on the main board which creates a voltage called 5V General. This 5V General now provides the pull up voltages which supply the output control circuits to the SMPS. The RL ON enters the SMPS Board (Pin 19 of P813). At the same time, the 5V General voltage also creates a signal called 5V Det. This is routed to the main Micon and to the SMPS (Pin 17 PG813) notifying the SMPS sub-Micon that the main board is functioning. The RL ON Voltage is sensed by the Sub Micon (IC701) circuit which causes the Relay Drive Circuit to close both Relays RL101 and RL103 bringing the PFC source up to full power by increasing the 90V standby to 340V which can be read Fuse F801. At this time the 17V and 12V sources becomes active and are sent to the Main Board via P813. (17V pins 1 and 2 and 12V at pins 5 and 6 of P813)

The next step is for the Micon (IC1) on the Main Board to output a high on M5V ON Line to the SMPS at P813 Pin 21

which is sensed by the Sub Micon IC (IC701) on the SMPS turning on the M5V line from P811pins 9 and 10 to the Y-SUS

board.

The last step to bring the supply to “Full Power” occurs when the Micon (IC100) on the Main Board brings the VS-ON line high at Pin 20 of P813 on the SMPS Board which when sensed by the Sub Micon IC (IC701) turns on the VA and VS Supplies (VA pins 6 and 7 is brought high before VS pins 1 and 2) and output from P811 to the Y-SUS board.

Preliminary Information 42PQ30

Page 37

42PQ30 POWER SUPPLY TURN ON COMMANDS FROM MAIN PWB

Det.

AC In

Turns on Red LED

In Stand-By

Primary side is

90V

Stand

By 5V Reg

In Run (Relay On)

Primary side is

370V

12V/16V

Regulators

Stand

By 5V

Det.

12V

Relay

17V

23 55 66 7

12V

Reg

Video

M5V OnVs

16V

Audio

M5V

Reg

M5V (DC Voltage)

Also develops 15V

Vs/Va (DC Voltage)

15V

Vs from

Y-SUS

5V and 15V

From Y-SUS to

15V 5V

Det.

Both LEDs On

Looks Amber

Resets

Main Board

Turns on

Green LED

Microprocessor or

Relay On

BCM

At point TV is in Stand-By state. Energy Star compliant. Less than 1 Watt

Power

Va From Y-SUS

Remote

Or Key

Page 38

Power Supply Generic Troubleshooting Tips

Remember if a voltage is missing check for proper resistance before proceeding

Understanding the Power On Sequence when Troubleshooting a possible Power Supply Failure will simplify the process of isolating which circuit board failed to operate properly. In this Section we will investigate the Power on Sequence and examine ways to locate quickly where the failure occurred.

When Power is pressed, listen for a Relay Click, the click of the Relay is an indication of RL-ON going high. RL-ON is sent from the Main Board to the SMPS and when present the IC701 controls the operation of both Relays. RL-ON going High and no Relay is a failure of the SMPS, RL-ON staying low is a failure of the Main Board or something between.

Relay Operation means that the SMPS if working properly will output the 17V and 12V Supplies t o the Main Board. These voltages will allow the Tuner, Audio and Video Circuits on the Main Board to function and if connected to an Antenna Input, Audio would be present. If the Relays closes and these supplies failed suspect a problem with the SMPS or an excessive load on the line.

The next step of operation calls for the M5V ON line from the Main Board to the SMPS to go high on P813 pin 21. A high on the M5V ON Line activates the M5V line to the Y-SUS Board. Loss of M5V results in no “Raster”, no Display Panel Reset, no Y, Z, Control or X Board operation. Loss of M5V and/or M5V ON going high could be caused by any of these boards or failure of the SMPS. M5V ON staying low indicates a problem on the Main Board.

VS-ON is the last step of the Power Sequence and is responsible for bringing the VS and VA Voltages up. The VS ON signal pin 20 P813 is sent from the Main Board to the SMPS as a high, VS and VA and full operation of the Display Panel are now enabled. Loss of VS-ON results in loss of VA and VS and no Raster, no Panel Display Reset but Audio would be present. If VS-ON went high and VS and VA where missing the problem could be caused by a failure on the SMPS or a circuit using these voltages. A Resistance check should narrow the possible failures quickly.

Preliminary Information 42PQ30

Page 39

Switch Mode Power Supply Static Test

This test can confirm the proper operation of the SMPS without the need to exchange the board. This Power Supply can operate in a No Load State. This means that by applying AC power to SC101 and all other plugs disconnected, this power supply will function. Simply removing P813 (Lower Right Hand Side of the PWB), will cause the “AUTO” Pin 22 to go high from its normal low state allowing the Power Supply to go to full power on mode when AC Power is Supplied. Be careful after this test and make sure the VA and VS lines have

discharged before reconnecting the supply cables.

For a “Stand-Alone” static test for the Power Supply, apply the usual 2 100Watt light Bulbs in series

test between Vs output and chassis ground for a simulated 200Watt load. If the Power Supply operates in this condition, it is assured it can maintain its output power under load.

If the Y-SUS, Z-SUS and X PWBs are working normal, when the SMPS comes up to full power on, “Display Panel Reset” will be visible. Shorting the Auto Pattern Gen. test points at this time should result with test patterns on the screen.

If either Y-SUS or Z-SUS is causing the power supply to shutdown, unplug the Z-SUS.

(Remember, Vs is routed to the Z-SUS PWB P3 from the Y-SUS P206 pins 1 & 2.

This will allow the Y-SUS to function. Also, if you unplug the Y-SUS from the SMPS and jump the 5V VCC line to any 5V location on the Control Board the Control PWB will function.

Preliminary Information 42PQ30

Page 40

Gnd

100W

1 2

Also check

Pins 6 or 7 for

proper Va

42PQ30 SMPS (LIGHT BULB) STATIC TEST UNDER LOAD

Using two 100 Watt light bulbs, attach on end to Vs and the other end to ground. Apply AC to SC101. If the light bulbs turn on, allow the the SMPS to run for several minutes to be sure it will operate under load. If this test is suscessful and all other voltages are

generated, you can be assured the power supply is OK.

P811

L602

T901

L601

Both F801

and F302 read from

Rectifier

Hot Gnd

F801

Primary Bridge

Hot Ground

RL101

4A/250V

Stby 338V

Run 388V

Hot Ground

F302

1A/250V

Stby 338V

Run 388V

RL103

Hot Ground

8A/250V

VR901

T30

AC In

SC101

VR502

IC701

P813

The Main PWB will

not function without

STBY 5V and AC Det

arriving from the

SMPS.

Check Pins 9, 10, 11

or 12 for 5V-STBY

Check Pin 18 for

AC Det 5V

Any time AC is

applied to the

SMPS, STBY 5V

and AC DET should

be present.

Check Pins 1 or 2

for 17V

Check Pins 5 or 6

for 12V

Note: The light bulb test is not necessary for the SMPS to turn on and stay on. This SMPS will run without a load. But it is necessary to test the SMPS under a load.

Page 41

Switch Mode Power Supply Static Test (Forcing on the SMPS in sta

P811 and P813 are removed

(A) Ground the Auto Ground (Pin 22) on P813

ges)

from the Power Supply

Remove AC apply the next

step and then reapply AC

(a) When AC Power is applied, Check AC Det (Pin 18) and 5V Stand-By (Pins 9 ~ 12) are 5V.

(B) 100Ω ¼ watt resistor added from 5V STB (Pins 9 ~ 12)

to RL ON (Pin 19) closes relay RL101 and RL103 turning on the 17V and 12V Supplies.

(BC 100Ω ¼ watt resistor added from 5V STB (Pins 9 ~ 12) to M5 ON (Pin 21) brings the M5V (P811

pins 9, 10) line high.

(D) 100Ω ¼ watt resistor added from 5V STB (Pins 9 ~ 12) to VS ON (Pin 20) brings the VA and VS

(P811 pins 1 and 2 Vs and Pins 6 and 7 Va) Lines high

Preliminary Information 42PQ30

Page 42

SMPS Va and Vs Adjustments

Use Full White Raster

“White Wash”

Va TP

P811

Pin 6 or 7

Pull P813.

Apply AC Power.

Power Supply Starts

Automatically.

This Power Supply will

come up and run with

“NO” load on

P811.

But, check using 200W

light bulb test.

With P811 in circuit,

Y & Z SUS Run.

Both Y and Z waveforms

are generated.

Vs TP

P811

Pin 1 or 2

Important: Use the Panel Label Not this book for all voltage adjustments.

Preliminary Information 42PQ30

Page 43

SC101 and P811 Pin ID and Voltages

Voltage and Resistance Measurements for the SMPS.

SC101 AC INPUT

Standby Run Diode ModeConnector Pin Number

SC101 120VAC 120VAC Open

P811 CONNECTOR "Power Supply PWB“ to Y-SUS

1 and 3

Diode ModeRun STBYLabelPin

Open*194V0VVs1

Open*194V0VVs2

Gnd0V0VGnd3

n/cn/cn/cn/c4

Gnd0V0VGnd5

Open*60V0VVa6

Open*60V0VVa7

Gnd0V0VGnd8

2.99V5V0VM5V9

* Note: This voltage will vary in accordance with Panel Label

Diode Mode Readings taken with all connectors Disconnected. DVM in Diode Mode.

Preliminary Information 42PQ30

2.99V5V0VM5V10

Page 44

P813 Odd Pins ID and Voltages

Voltage and Diode Mode Measurements for the SMPS (Page 1 of 2)

P813 CONNECTOR “SMPS" to “Main PWB" P301

Diode ModeRun STBYLabelPin

Open17.3V0V17V1

GndGndGndGnd3

Open12V0V12V5

GndGndGndGnd7

1.1V5V5V5V9

1.1V5V5V5V11

GndGndGndGnd13

GndGndGndGnd15

3.1V5V.15V5V Det17

Open3.73V0VRL On19

Open3.24V0VM5 ON21

Open5V5VStby 5V23

Auto Gnd

Diode ModeRun STBYLabelPin

Open17.3V0V17V2

GndGndGndGnd4

Open12V0V12V6

GndGndGndGnd8

1.1V5V5V5V10

1.1V5V5V5V12

GndGndGndGnd14

Not UsedGndGndGnd16

1.0V5V5VAC Det18

Open3.2V0VVS On20

OpenGndGnd

Open0V0VKey On24

Diode Mode Readings taken with all connectors Disconnected. DVM in Diode Mode.

Preliminary Information 42PQ30

Page 45

SUS PWB SECTION (Overview)

YY--SUS PWB SECTION (Overview)

Y-SUS Board develops the Y-Scan to the Y-Drive boards.

This Section of the Presentation will cover troubleshooting the Y-SUS Board for the Single Scan Plasma. Upon completion of the Section the technician will have a better understanding of the operation of the circuit and will be able to locate voltage and resistance test points needed for troubleshooting and alignments.

• Adjustments

• DC Voltage and Waveform Checks

• Resistance Measurements

Operating

SMPS Supplied VA

Y-Z SUS Developed -VY VR502

Floating Ground FG 5V

Voltages

VS M5V

VSC VR501 V SET UP VR601

V SET DN VR602 15V

VA supplies the Panel Vertical Grid (Routed to the X-Boards)

VS Supplies the Panel Horizontal Grid (Also routed to the Z-SUS)

5V Supplies Bias to Y-Z SUS, (Routed to the Control Board)

-VY Sets the Negative excursion of the Y SUS Drive Waveform VSC Set the amplitude of the complex waveform. Ramp UP sets amplitude of the Top Ramp of the Drive Waveform V Set Down sets the Pitch of the Bottom Ramp of the Drive Waveform To the Control Board then routed to the Z-SUS board Used on the Y-Drive boards (Measured from Floating Gnd)

Preliminary Information 42PQ30

Page 46

SUS PWB Layout

YY--SUS PWB Layout

P203, P208, P205 and P207

Plugs into Y-Drive board

Pin 1 Y-SUS opposite on Y-Drive

Y-Drive board

P203

P203, P208 and P205

All Floating Ground

P208

P205

P207 Pins 1 and 2

Y Scan signal

VSC TP

R520/J263

-VY TP R201

FS202 (Vs)

4A 250V

SET UP

VR 601

FS201(5V)

V SET DN

VR 401

P201

VS, VA and M5V Input from the SMPS

P206

FS203 (Va)

Vs to Z-SUS

10A

Floating Gnd 5V

Pins 4 and 5

Pins 7, 8, 9, 10 and 11

Logic (Drive) Signals to

the Y Drive PWBs

P207

VSC ADJ

VR501

-VY ADJ VR502

15V TP

J269

5V and 15V

P101

Ribbon

P202

Logic Signals from the Control PWB

P202

Va to Left X Board Pins 1, 2 and 3

Preliminary Information 42PQ30

Page 47

SUS PWB P207 Explained

YY--SUS PWB P207 Explained

Use the Left Side of C213 to test for Y Scan signal

Y-Drive Board Y-SUS Board

P205

FL1

P104

P207

1. Scan Sig

2. Scan Sig

3. n/c

4. 5V FG

5. 5V FG

6. SUS Dn

7. CLK

8. STB

9. OC1

10. DATA

11. n/c

12. SUS_Dn

Bottom Connector P207

P207 Pins 1 and 2

Y Scan signal

5V measured from

Floating Gnd

Pins 4 or 5 P207

P207 Pins 7, 8, 9, 10 and 11

Logic (Drive) Signals to the Y

Drive PWBs

Preliminary Information 42PQ30

Page 48

VSC and --

VSC and

Y SUSTAIN ADJUSTMENT DETAILS

These are DC level

Voltage Adjustments

VY Adjustments

CAUTION: Use the actual panel label and not the book for exact voltage settings.

Voltage Reads Positive

-Vy TP R201

-Vy VSC

Lower

Left Side

Of PWB

-Vy TP

VR501

VR502

Vsc TP

Set should run for 15 minutes, this is the “Heat Run” mode. Set screen to “White Wash” mode or 100 IRE White input.

Adjust –Vy to Panel Label voltage (+/- 1V) Adjust VSC to Panel Label voltage (+/- 1V)

Just below Heat Sinks

VSC TP R520 / J263

J263

R520

Lower Left Side of PWB

Preliminary Information 42PQ30

Page 49

Drive Signal Overview

YY--Drive Signal Overview

Y-Drive PWB Test Point

(Top of Y-Drive Board)

c Overall signal observed 4mS/div

d Highlighted signal from waveform

above observed 400uS/div

528V p/p

e Highlighted signal from

waveforms above observed

100uS/div

NOTE: The Waveform Test Point is fragile. If by accident the land is torn and the run lifted, make sure there are no lines left to right in the screen picture. NOTE: The two test points just below and to the left will also work for the Y-Drive waveform Test Point.

100uS

Preliminary Information 42PQ30

Page 50

Observing (Capturing) the Y--

Observing (Capturing) the Y

Drive Signal for

Vsetup

Ramp--

Ramp

Up (RAMP)

Set must be in “WHITE WASH” All other DC Voltage adjustments should have already been made.

Fig 1:

As an example of how to lock in to the Y-Drive Waveform. Fig 1 shows the signal locked in at 4ms per/div. Note the 2 blanking sections. The signal for SET-UP is outlined within the Waveform

Fig 2:

At 2mSec per/division, the waveform to use for

SET-UP Is now becoming clear.

Fig 3:

At 400us per/div. the signal for recognize. It is outlined within the Waveform

SET-UP is now easier to

Outlined

Area to

be adjusted

Area to

be adjusted

Area

Blanking

Blanking Blanking

FIG1 4mS

FIG2 2mS

FIG3 400uS

Fig 4:

At 40uSec per/division, the adjustment for

SET-UP can be made.

Area to

be adjusted

Preliminary Information 42PQ30

FIG4 40uS

Page 51

Observing (Capturing) the Y--

Observing (Capturing) the Y

Drive Signal for

Vsetup

Ramp--

Ramp

Down

Set must be in “WHITE WASH” All other DC Voltage adjustments should have already been made.

Fig 1:

As an example of how to lock in to the Y-Drive Waveform. Fig 1 shows the signal locked in at 4ms per/div. Note the 2 blanking sections. The signal for SET-DN is outlined within the Waveform

Fig 2:

At 2mSec per/division, the waveform to use for

SET-DN is now becoming clear.

Fig 3:

At 400us per/div. the signal for recognize. It is outlined within the Waveform

SET-DN is now easier to

Outlined

Area to

be adjusted

Area to

be adjusted

Area

Blanking

Blanking Blanking

FIG1 4mS

FIG2 2mS

FIG3 400uS

Fig 4:

At 40uSec per/division, the adjustment for can be made.

SET-DN

Area to

be adjusted

Preliminary Information 42PQ30

FIG4 40uS

Page 52

Set Up and V--

VV--Set Up and V

Y SUSTAIN ADJUSTMENT DETAILS (Vs, Va, VSC and –VY must have already been completed). Set in White Wash.

Observe the Picture while making these adjustments. Normally, they do not have to be done.

Y-Drive PWB Test Point

Set Down Adjustments

SET-UP ADJUST:

1) Adjust VR601 and set the (A) portion of the signal to match the waveform above.

SET-DN ADJUST:

2) Adjust VR401 and set the (B) time of the signal to match the waveform above.

ADJUSTMENT LOCATION:

Just to the bottom right of the right hand heat sink.

Preliminary Information 42PQ30

Page 53

V Set Up Too High or Low

Panel Waveform Adjustment

Ramp (Vset UP) too high

Ramp (Vset UP) too low

The center begins to wash out and arc due to Vset UP Peeking too late and alters the start of the Vset DN phase.

Very little alteration to the picture, the wave form indicates a distorted Vset UP. The peek widens due to the Vset UP peeking too quickly.

Preliminary Information 42PQ30

Page 54

V Set

Too High or Low

Vset Dn swing is Minimum 110uS Max 200uS+

Vset DN too high

Panel Waveform Adjustment

NOTE: If Vset DN too high, this set will go to excessive bright, then shutdown. To correct, remove the LVDS from control PWB and make necessary adjustments.

All of the center washes out due to increased Vset_DN time.

Vset DN too low

The center begins to wash out and arc due to decreased Vset DN time.

Preliminary Information 42PQ30

Page 55

Y SUS Block Diagram

Block Diagram of Y-Sustain Board

Left X Board

Distributes VA

Circuits generate

Y Sustain Waveform

Power Supply Board - SMPS

Receive M5V, Va, Vs

from SMPS

Generates Vsc and -Vy

from Vs by DC/DC Converters

Also controls Ramp Up/Down

FETs amplify Sustain

Waveform

Z-SUS Board

Distributes 15V

Distributes 15V and 5V

Control Board

Logic signals

needed to

generate drive

waveform

Generates Floating Ground

5V by DC/DC Converters

Y Drive Board

Receives Scan Waveform

Display Panel

Preliminary Information 42PQ30

Page 56

SUS How to Check the Output FETs

YY--SUS How to Check the Output FETs

Name is printed on the components. Readings “In Circuit”.

IRFP4332

Forward: 0.5V ~ 0.7V Reverse: 1.1V

IRGP4086 IRGP4086

Forward: 0.6V ~ 0.7V Reverse: 1.3V

RF2001

Forward: Shorted Reverse: Shorted

30N45T

Forward: 0.6V Reverse: Shorted

RF2001

Forward: 0.4V

Forward: 0.4V Reverse: Open

Reverse: Open

30N45T

Forward: 0.6V Reverse: Shorted

IRFP4332

Forward: 0.4V ~ 0.5V Reverse: Open

Forward: 0.39V ~ 0.5V Reverse: Open

IRFP4332

Forward: 1.6V Reverse: Open

IRGP4086

Forward: 0.6V ~ 0.7V Reverse: 1.3V

RF2001

Forward: 0.38V Reverse: Open

IRGP4086

Forward: 0.39V ~ 0.5V Reverse: Open

K3667

Forward: 0.22V Reverse: Open

K3667

Forward: 0.5V Reverse: Open

K3667

Forward: 0.4V ~ 0.5V Reverse: Open

Preliminary Information 42PQ30

Page 57

SUS P201 to SMPS P812 Plug Information

YY––SUS P201 to SMPS P812 Plug Information

Voltage and Resistance Measurement

P201 CONNECTOR "Y-SUS" to "Power Supply PWB" P811

Diode ModeRun STBYLabelPin

Open*193V0VVs1

Open*193V0VVs2

NCNCNCNC3

GndGndGndGnd4

GndGndGndGnd5

Open*60V0VVa6

* Note: This voltage will vary in accordance with Panel Label

Diode Mode Readings taken with all connectors Disconnected. DVM in Diode Mode.

Open*60V0VVa7

GndGndGndGnd8

1.1V5V0VM5V9

1.1V5V0VM5V10

Preliminary Information 42PQ30

Page 58

SUS P202 to X Drive P211 and P311 Plug Information

YY--SUS P202 to X Drive P211 and P311 Plug Information

Voltage and Diode Mode Measurements for the Y SUS Board

P202 CONNECTOR "Y-SUS PWB" to "X-Drive” Left P233

Diode ModeRun STBYLabelPin

GndGndGndGnd1

GndGndGndGnd2

GndGndGndGnd3

ncncncnc4

Open*60V0VVA5

Open*60V0VVA6

* Note: This voltage will vary in accordance with Panel Label

Diode Mode Readings taken with all connectors Disconnected. DVM in Diode Mode.

Open*60V0VVA7

Preliminary Information 42PQ30

Page 59

SUS P801 to Z Drive P1 Plug Information

YY--SUS P801 to Z Drive P1 Plug Information

Voltage and Diode Mode Measurements for the Y SUS Board

P206 Connector Y-SUS to Z Drive P1 Plug Information

Diode ModeRun STBYLabelPin

Open* 94.9V0VEr Com1

Open*94.9V0VEr Com2

ncncncnc3

GndGndGndGnd4

GndGndGndGnd5

ncncncnc6

* Note: This voltage will vary in accordance with Panel Label

Diode Mode Readings taken with all connectors Disconnected. DVM in Diode Mode.

Open*193V0VVS7

Gnd*193V0VVS8

Preliminary Information 42PQ30

Page 60

P101 Y--

P101 Y

Voltage Measurements for the Y SUS Board

These connector pins are too close to read without possible damage to the PWB

Actually a 30 Pin Connector “Measurements can be made on the Control PWB

SUS to Control PWB P111 Plug Information

Y-SUS Board B+ checks for the P101 connector.

FS201

5V to run the Control Board.

Also sent to the Z-SUS Board.

Routed through the Control Board.

Leaves the Control Board on P101 pins 10.

Run: 5VStandby: 0V Diode Check: 1.1V

FS501

15V to run the Z-SUS Board.

Routed through the Control Board.

Leaves the Control Board on P101 pins 11 and 12.

Run: 15VStandby: 0V Diode Check: 0.78V

Preliminary Information 42PQ30

Page 61

SUS P101 to Control P111 Plug Information

YY--SUS P101 to Control P111 Plug Information

“Y-SUS" P101 CONNECTOR to “Control PWB" P111

Diode ModeRun STBYLabelPin

Gnd0VGndGnd1

0.65V0.1V0Vn/a3

0.65V1.28V0Vn/a5

0.65V0V0Vn/a7

0.65V0.6V0Vn/a9

0.65V2.96V0Vn/a11

0.65V1.4V0Vn/a13

0.65V0V0Vn/a15

0.65V1.89V0Vn/a17

0.65V2.16V0Vn/a19 GndGndGndGnd21 GndGndGndGnd23

0.44V5V0V5V25

Diode ModeRun STBYLabelPin

0.65V0.12V0Vn/a2

0.65V0.13V0Vn/a4

0.65V0.2V0Vn/a6

0.65V1.05V0Vn/a8

0.65V0.17V0Vn/a10

0.65V2.5V0Vn/a12

0.65V0V0Vn/a14

0.65V0V0Vn/a16 Open0V0Vn/a18

GndGndGndGnd20 GndGndGndGnd22

0.44V5V0V5V24

0.44V5V0V5V26

0.44V5V0V5V27 Open15V0V15V29

Diode Mode Readings taken with all connectors Disconnected. DVM in Diode Mode.

0.44V5V0V5V28 Open15V0V15V30

Preliminary Information 42PQ30

Page 62

SUS P207 Voltage Readings

YY--SUS P207 Voltage Readings

All voltages taken from Floating Ground.

Warning: Do not hook scope ground up unless set plugged into an

P207

Pin Label Voltage

1) VSC 140V

2) VSC 140V

3) Nc

4) 5V VF 5V

5) 5V VF 5V

6) SUS_DN FGnd

7) CLK 0.96V

8) STB 2.3V

9) OC1 2.3V

isolation transformer.

10) DATA 0V

11) Nc

12) SUS_DN FGnd

Preliminary Information 42PQ30

Page 63

SUS P207 (Drive Output Plug) TESTING

YY--SUS P207 (Drive Output Plug) TESTING

P104 OF THE

Y-DRIVE PWB

P207 OF THE

Y-DRIVE PWB

Disconnected from the Y--

Disconnected from the Y

Y Drive Sig Y Drive Sig

Floating Gnd

CHECKING THE Y--

CHECKING THE Y

SUS PWB

DRIVE PWB

Readings from Floating Ground (Pin 1)

BLACK LEAD

Red Lead FG

Open Open Open

0.52V

0.52V 0V

0.59V

0.63V

0.59V

0.65V 0V

1.) VSC

2.) VSC

3.) nc

4.) FG+5V

5.) FG+5V

6.) SUS Dn

7.) CLK

8.) LE

9.) OC1

10.) Data

11.) nc

12.) SUS Dn

RED LEAD

Blk Lead FG

Open Open Open

1.78V

1.78V 0V

1.57V

1.67V

1.57V

1.67V 0V

Pin 1

Floating

Ground

Pin 1 on Y-SUS

is backwards

compared to

Y-Drive

Meter in the Diode Mode

Preliminary Information 42PQ30

Page 64

DRIVE PWB SECTION (Y--

YY--DRIVE PWB SECTION (Y

Y-Drive Board works as a path supplying the Sustain and Reset waveforms which are

made in the Y SUSTAIN PWB and sent to the Panel through SCAN DRIVER IC’s.

The Y Drive Boards supply a waveform which selects the horizontal electrodes

sequentially.

* 42PQ30 uses 8 DRIVER ICs on 1 Y Drive Board

Drive Explained)

Y DRIVE WAVEFORM

Y DRIVE WAVEFORM TEST POINT

To facilitate scope attachment, solder a small wire (Stand Off) at this point.

Preliminary Information 42PQ30

Page 65

Y Drive PWB ID

5 Volts, Y Drive and Logic Signals from Y SUS Board are supplied to the Drive Board on Connectors P104.

Y Drive Scan

Signal Input

Y-SUS

SIDE

TOP BOTTOM

PANEL

SIDE

Floating Ground from the Y SUS Board P101, P103, P102 and pins 1 and 7 of P104

P101

P103 P102 P104

FL1

Floating Gnd

+5V

Y Drive and Logic Signals

(Clock and Data) from the

Y SUS Board

Check 5V supply using FL1 or across C18. Measured from Floating Ground

Y Drive Scan (VSC) Signal Input TP Or measure at Pins 1 and 2 of P104

Preliminary Information 42PQ30

Page 66

Y Drive P207 Voltage Readings

All voltages taken

from Floating

Ground.

Warning: Do not

hook scope ground

up unless set

plugged into an

isolation

transformer.

Pin Label Voltage

1) VSC 140V

2) VSC 140V

3) Nc

4) 5V VF 5V

5) 5V VF 5V

6) SUS_DN FGnd

7) CLK 0.96V

8) STB 2.3V

9) OC1 2.3V

10) DATA 0V

11) Nc

12) SUS_DN FGnd

Preliminary Information 42PQ30

Page 67

Drive PWB Buffer Troubleshooting

YY--Drive PWB Buffer Troubleshooting

Disconnected from the Y--

Disconnected from the Y

Y Drive Sig Y Drive Sig

Floating Gnd

CHECKING THE Y--

CHECKING THE Y

DRIVE PWB

SUS PWB

Readings from Floating Ground (Pin 1)

BLACK LEAD

Red Lead FG

Open Open Open Open Open 0V

2.9V

2.9V Open Open Open 0V

12.) VSC

11.) VSC

10.) nc

9.) FG+5V

8.) FG+5V

7.) SUS Dn

6.) CLK

5.) LE

4.) OC1

3.) Data

2.) nc

1.) SUS Dn

RED LEAD

Blk Lead FG

1.15V

1.15V Open

0.4V

0.4V 0V

0.5V

0.62V

0.48V 0V

P104 OF THE

Y-DRIVE PWB

P207 OF THE

Y-DRIVE PWB

Meter in the Diode Mode

Pin 1

Floating

Ground

Pin 1 on Y-SUS

is backwards

compared to

Y-Drive

Preliminary Information 42PQ30

Page 68

Removing (Panel) Flexible Ribbon from Y Drive

Flexible Ribbon Cables shown are from a different model, but pro

To remove the Ribbon Cable from the connector first carefully lift the Locking Tab from

the back and tilt it forward ( lift from under the tab as shown in Fig 1). The locking tab must be standing straight up as shown in Fig 2. Lift up the entire Ribbon Cable gently to release the Tabs on each end. (See Fig 3) Gently slide the Ribbon Cable free from the connector.

Gently Pry Up Here

cess is the same.

Be sure ribbon tab is released By lifting the ribbon up slightly Before removing ribbon.

Fig 3

Locking tab in upright position

Fig 1

To reinstall the Ribbon Cable, carefully slide it back into the slot see ( Fig 3 ), be sure the Tab is seated securely and press the Locking Tab back to the locked position see ( Fig 2 then Fig 1).

Fig 2

Preliminary Information 42PQ30

Page 69

Y Drive Flexible Ribbon Incorrectly Seated

The Ribbon Cable is clearly improperly seated into the connector. You can tell by observing the linearity.

The Locking Tab will offer a greater resistance to closing in the case.

Note the cable is crooked. In this case the Tab on the Ribbon cable was improperly seated at the top. This can cause bars, lines, intermittent lines abnormalities in the picture.

Remove the ribbon cable and re-seat it correctly.

Preliminary Information 42PQ30

Page 70

Y Drive BUFFER Troubleshooting

YOU CAN CHECK ALL 8 BUFFER ICs USING THIS PROCEDURE

BACK SIDE OF Y-DRIVE PWB

BUFFER IC FLOATING GROUND (FGnd)

128 Output Pins

Using the “Diode Test” on the DVM, check the pins for shorts or abnormal loads.

RED LEAD ON

BUFFER IC FGnd

Indicated by white outline

BLACK LEAD ON

BLACK LEAD ON “ANY”

OUTPUT LUG.

READING 0.78 V

RED LEAD ON “ANY”

43 43 42

• Any of these output lugs can be tested.

• Look for shorts indicating a defective Buffer IC

BUFFER IC FGnd

Indicated by white outline

128 Output Pins per/buffer

6 Ribbon cables (Horizontal Grids)

768 Total Horizontal Grids controlling Vertical resolution

OUTPUT LUG.

READING “OPEN”

Preliminary Information 42PQ30

Page 71

Troubleshooting the Z--

Troubleshooting the Z

SUS Drive section of the Y--

SUS Drive section of the Y

SUS PWB

This Section of the Presentation will cover troubleshooting the ZZ--

This Section of the Presentation will cover troubleshooting the

Assembly. Upon completion of this section the Technician will ha

circuit and be able to locate voltage and resistance test points

alignment.

Locations

• DC Voltage and Waveform Test Points

• Z BIAS Alignment

• Resistance Test Points

Operating Voltages

Y SUS Supplied VS

Drive section of the Y--ZZ--

Drive section of the Y

ve a better understanding of the

needed for troubleshooting and

SUS Board

5V Vcc

Developed on Y SUS

Preliminary Information 42PQ30

15V

Z Bias

Page 72

SUS Board Layout

ZZ--SUS Board Layout

No IPMs

Read the Label on the back of the

upper left hand side of the panel.

Waveform

Development

VS Input from

the Y-SUS

Z SUS

ICs

Z-Bias ADJ VR8

Z SUS

Output

ICs

Z SUS Waveform Test Point

J27

Z Bias

FPC

Logic Signals from the Control PWB

Also +15V and +5V

VZ (Z-Bias) TP

Right side

R49 or R50

Preliminary Information 42PQ30

Page 73

SUS Waveform

ZZ--SUS Waveform

Provides the SUSTAIN PULSE and ERASE PULSE for generating SUSTAIN discharge in the panel by receiving Drive signals from the Y-Z-SUS PWB.

This waveform is supplied to the panel through FPC (Flexible Printed Circuit).

Z-Bias is a “DC” adjustment. The effects of this adjustment can be observed on the scope looking at the Z-SUS output.

Z Drive Waveform

Z-SUS

PWB

(Vzb) Z Bias VR8

Vzb voltage

1V80 V

400uS/div50V/div

This Waveform is just for reference to observe the effects of Zbz adjustment

Note: The Vzb Adjustment is a

Preliminary Information 42PQ30

Oscilloscope Connection Point.

J27 to check Z Output waveform.

Right Hand side Center.

DC level adjustment

Page 74

VZ (Z--

VZ (Z

Bias) Adjustment

Read the Label on the back of the

upper left hand side of the panel.

Adjust using VR8.

Z Bias

VR8

Bottom Center of Z-SUS Board

Set should run for 15 minutes, this is the “Heat Run” mode. Set screen to “White Wash” mode or 100 IRE White input.

VZ (Z-Bias) TP Right

Side R49 or R50

Measured from Chassis Ground

Adjust VZ (Z-Bias) to Panel Label (± 1V)

Preliminary Information 42PQ30

Page 75

SUS Block Diagram

ZZ--SUS Block Diagram

Diagram of Z Sustain Board

NO IPMs

Distributes Logic Signals

Control Board

5V, 15V

Circuits generate erase,

sustain waveforms

POWER SUPPLY Board

M5V, VA, VS

Y-SUS Board

Z-SUS PWB Receives VS from

Y-SUS and 15V, 5V from

Control PWB

Generates Z Bias 100V

FET Makes Drive waveform

Display Panel

Via FPC

(flexible printed circuit )

Preliminary Information 42PQ30

Page 76

SUS P3 Connector to Y--

ZZ--SUS P3 Connector to Y

Voltage and Diode Mode Measurements

P3 CONNECTOR “Z-SUS PWB" to “Y-SUS Out" P206

SUS P206 Voltages and Resistance

Diode ModeRun STBYLabelPin

Open*94.9V0VER COM1

Open*94.9V0VER COM2

Openncncnc3

GndGndGndGnd4

GndGndGndGnd5

Openncncnc6

* Note: This voltage will vary in accordance with Panel Label

Diode Mode Readings taken with all connectors Disconnected. DVM in Diode Mode.

Open*193V0VVS7

Open*193V0VVS8

Preliminary Information 42PQ30

Page 77

SUS P2 Connector to Control P101 Voltages and Resistance

ZZ--SUS P2 Connector to Control P101 Voltages and Resistance

Voltage and Diode Mode Measurements

P2 CONNECTOR “Z-SUS PWB" to “Control" P101

Diode ModeRun STBYLabelPin

2.8V0.79V0VZ SUS DN1

2.8V0.13V0VZ SUS UP2

2.8V0.19V0VZ ER UP3

2.8V0.4V0VZ ER DN4

2.8V1.9V0VZ BIAS5

Open0.8V0VOE6

Open1.9V0VCTRL_OE7

GndGndGndGnd8

GndGndGndGnd9

Open4.9V0V+5V10

Open16.9V0V+15V11

Open16.9V0V+15V12

Pin 1 on Left side of connector

Diode Mode Readings taken with all connectors Disconnected. DVM in Diode Mode.

Preliminary Information 42PQ30

Page 78

CONTROL PWB SECTION

This Section of the Presentation will cover troubleshooting the Control Board Assembly. Upon completion of this section the Technician will have a better understanding of the circuit and be able to locate voltage and resistance test points needed for troubleshooting.

• DC Voltage and Waveform Test Points

• Resistance Test Points

Signals

Main Board Supplied LVDS Signal

Control Board Generated Y and Z Sustain Drive Signals (Luminance)

X Board Drive Signals (Color)

Operating Voltages

Y SUS Supplied +5V (Also Routed to the Z-SUS)

+15V (Routed to the Z-SUS)

Developed on the +1.8V

Control board

(2) +3.3V

Preliminary Information 42PQ30

Page 79

Control PWB Identified

Waveform Generation Software

Download Connection

n/c

P131

P121

To P1002

Main

LVDS

X101

Crystal 25Meg

1.8V

FL111 FL112

To P101

Y-SUS

P111

3.3V

IC221

3.3V

IC252

ROM

IC101

FL204

Protect

IC231

IC201

MCM

AUTO GEN TEST

PATTERN

4.8V

IC211

EEPROM

D201

Data

LED

Label

Part Number

Vs DA

3.2V

IC1

1) 3.3V

2) 0V

3) 3.3V

4) 0V

5) 3.3V

6) 3.3V

7) 0V

8) 3.3V

IC1

Pin 1

P101

To P2

Z-SUS

P161

To X Drive Left

P162

Preliminary Information 42PQ30

Page 80

Control PWB Pictorial

Note: IC221 (3.3V Regulator) routed

out P161 / P162 to X-PWBs

Preliminary Information 42PQ30

Page 81

Control PWB Testing

For quick PWB test. (All PWB connectors Disconnected).

Jump 5V from Power Supply to IC201 Pin 1. (Bottom Pin) If the LED blinks, Pretty much guaranteed, PWB is OK.

Confirm B+ to Control PWB VS_DA Control PWB Check 3V ~ 3.3V (Note, this TP can also be Used as an External Trigger For scope when locking onto the Y-Drive signal).

Quick observation

When the Television has a problem related to;

1) Shutdown caused by Main PWB

2) No Video (No Picture) Sound OK. This can be checked by the following. (1) Disconnect the Main PWB from all connectors. Apply AC power. Since P813 is not connected to the SMPS, the set will come on. Short the two pins on the Auto Test Pattern lands. If there is a picture of cycling colors and patters, the Y-SUS, Y-Drive, Z-SUS, Power Supply, Control PWB, X-Boards, TCPs and Panel are all OK. Use the same test for problem (2)above to tell if the No Video is caused by the Main PWB or failed LVDS cable.

Preliminary Information 42PQ30

Of LED blinking Tell if the Control Board is running.

Page 82

Checking the Crystal X101““

Checking the Crystal X101

X101

Clock””

Clock

on the Control Board

DC Voltage Check

1.5V ~ 1.8V

Osc. Check: 25Mhz

CONTROL

PWB CRYSTAL

LOCATION

Check the output of the Oscillator (Crystal). The frequency of the sine wave is 25 MHZ. Missing this clock signal will halt operation of the panel drive signals.

Preliminary Information 42PQ30

Page 83

Control LVDS Signals

Pins are close together, Use Main PWB side.

P1002 on Main Board

Connector P1002 Configuration

- indicates signal pins.

LVDS Cable P121 on Control PWB shown. Press two outside tabs inward to release.

LVDS

Video Signals from the Main Board to the Control Board are referred to as Low Voltage Differential Signals or LVDS. Their presence can be confirmed with the Oscilloscope by monitoring the LVDS signals with no input signal selected while pressing the Menu Button “on” and “off” with the Remote Control or Keypad. Loss of these Signals would confirm the failure is on the Main Board!

Pin c

Menu Off

Menu ON

Main PWB P1002

Example of Normal Signals measured at 200mv/cm at 5µs/cm .

Preliminary Information 42PQ30

Page 84

Control PWB Signal Block

The Control Board supplies Video Signals to the TCP (Tape Carrier Package) ICs. If there is a bar defect on the screen, it could be a Control Board problem.

Control Board to X Board

Address Signal Flow

This Picture shows Signal Flow Distribution to help determine the

failure depending on where the it shows on the screen.

MCM

EEPROM

IC201

DRAM

Basic Diagram of Control Board

IC201

MCM

CONTROL PWB

Resistor Array

16 line

2 Buffer Outputs per TCP

X-DRIVE PWB

PANEL

To X-Drive Boards

128 Lines per Buffer

256 Lines output Total

Preliminary Information 42PQ30

Page 85

Removing the LVDS Cable from the Control PWB

The LVDS Cable has two “Interlocks” that must be disengaged to remove the LVDS Cable. To Disengage, press the two Locking Tabs Inward and pull the plug out.

Press

Inward

Press

Inward

Preliminary Information 42PQ30

Page 86

Control PWB Connector P111 to Y--

Control PWB Connector P111 to Y

P111 These pins are very close together. When taking Voltage measurements use Caution.

FL111 and FL112 +5V Fuse

SUS P101 Voltages and Resistance

Pin c

Pins 1, and 2 Receive +15V from the Y-SUS.

Pins 3, 4, 5, 6, and 7 Receive +5V from the Y-SUS.

Pins 9, 10, 11 and 30 Are Ground

All the rest are delivering Y-Drive logic signals to the Y-SUS Board

The +15V is not used by the Control board, it is routed to the Z-SUS leaving on P101 Pins 11 and 12.

Odd

Pins

Even

Pins

Preliminary Information 42PQ30

Page 87

Control PWB Connector P111 Silkscreen Can Be Misleading

P111 The silkscreen indicates the left side is 1~15 and the right side is 16~30, however this is not correct. Use the normal Left Side Odd and Right Side Even pin configuration.

Silkscreen Label:

The pin numbers are

correct. Remember

Odd pins on the left

and even pins are on

the right.

Odd

Pins

Even

Pins

Pin c

Silkscreen Label:

The pin numbers are

correct. Remember

Odd pins on the left

and even pins are on

Example:

Pin d

the right.

Preliminary Information 42PQ30

Page 88

Control P111 to Y--

Control P111 to Y

SUS P101 Plug Information

P111 CONNECTOR “Control PWB" to “Y-SUS" P101

Diode ModeRun STBYLabelPin

Open15V0V15V1

0.97V5V0V5V3

0.97V5V0V5V5

0.97V5V0V5V7 GndGndGndGnd9 GndGndGndGnd11

Open0V0VOE13

2.8V0V0VSUS-DN15

2.8V0V0VER_DN17

2.8V2.5V0VSet_Up19

2.8V0.17V0VDummy 521

2.8V1.05V0VDummy 123

2.8V0.2V0VER_UP25

Diode ModeRun STBYLabelPin

Open15V0V15V2

0.97V5V0V5V4

0.97V5V0V5V6 GndGndGndGnd8 GndGndGndGnd10

2.8V2.16V0VDummy 212

2.8V1.89V0VOC214

2.8V0V0VData16

2.8V1.4V0VBLK18

2.8V2.96V0VSTB20

2.8V0.6V0VCLK22

2.8V0V0VDummy 324

2.8V1.28V0VDummy 426

2.8V0.13V0VSUS_UP27

2.8V0.12V0VSET_DN29

Diode Mode Readings taken with all connectors Disconnected. DVM in Diode Mode.

3.2V0.1V0VCTRL_OE28 GndGndGndGnd30

Preliminary Information 42PQ30

Page 89

Control P101 to Z--

Control P101 to Z

Diode Mode Readings taken with all connectors Disconnected. DVM in Diode Mode.

P101 CONNECTOR “Control PWB" to “Z-SUS" P2

SUS P2 Plug Information

Diode ModeRun STBYLabelPin

Open0.75V0VZ SUS Dn1

0.65V0.18V0VZ SUS Up2

0.65V0.16V0VZ ER Up3

0.65V0.3V0VZ ER Dn4

0.65V2V0VZ Bias5

0.65V0.07V0VOE6

0.65V0.06V0VCTRL_OE7

Pin 1 at the bottom

GndGndGndGnd8

GndGndGndGnd9

0.97V4.9V0V5V10

Open17V0V15V11

Open17V0V15V12

of the connector

Preliminary Information 42PQ30

Page 90

Control PWB Connector P161 and P162 to X--

Control PWB Connector P161 and P162 to X

P161 and P162 Connectors from the "Control PWB" to "X Drive These pins are covered with tape for transportation issues. (Tape can be removed).

Drive PWBs

P161

3.3V TP

Tape removed

3.3V TP

3.3V created

by IC221

P162

3.3V TP

The rest of the pins are much too

close together for a safe test.

Preliminary Information 42PQ30

Page 91

Left and Right X Drive (Commonly known as A--

Left and Right X Drive (Commonly known as A

BUS)

The X Drive PWBs deliver the Color drive signals to the Vertical Grids. The 42PQ30 has a Left and a Right X-Drive board. Each with 6 connectors to a TCP. And each TCP with 2 buffers. Each buffer controls 128 vertical grids lines.

Generally speaking, there isn’t many active components on the X-Drive PWBs (Printed Circuit Boards). So they are not prone to failure.

In this section the X-Drive will be discussed and information given allowing the service technician to determine if a failure has occurred in the X-Drive section.

X-BOARDS CONTROL THE VERTICAL GRIDS WHICH DETERMINE THE HORIZONTAL PIXEL COUNT. TOTAL HORIZONTAL GRIDS 3072. TOTAL HORIZONTAL PIXELS 1024.

Total Buffer Count = 24

(TCPs = 12 @ 2 buffers per/TCP)

Total Output Pins = 3072

(128 per buffer X 24 total)

Total Pixels (Horizontal) 1024

(3072 / 3) Three cells per pixel (Red, Green and Blue)

Preliminary Information 42PQ30

Page 92

Left and Right X Drive (Commonly known as A--

Left and Right X Drive (Commonly known as A

BUS)

Warning: DO NOT attempt to run the set with the Heat Sink over the TCPs removed. After a very short time, these ICs will begin to self destruct due to overheating.

LEFT X BOARD

P331 P311

P233 P211 P232

TCP IC

RIGHT X BOARD

TCP IC

TCP IC’s shown are part of the Ribbon Cable

Preliminary Information 42PQ30

Page 93

TCP (Tape

X Drive

Board

Carrier

Package)

TCP ICs supply RGB 16 bit signal to the PDP by connecting the

PAD Electrode of the PANEL with the X Board.

Front panel Horizontal Addr ess

Rear panel Vertical Address

Frame

Logic

X_B/D

Y-SUS Board

Control Board

nne

TCP

Taped Carrier

Package

TCP

Heat Sink

Back side of TCP Ribbon

Preliminary Information 42PQ30

Page 94

TCP Testing

On any Gnd

10,11,12,13,14,27,28,2 9,30,37,38,39,40,41

On any Va

4,5,6,7,44,45,46,47

Typical Reading 0.65V

Reverse leads Reading Open

Va VaGnd Gnd

5 10 15 20 25 30 35 40 45 501

Look for any TCPs being discolored. Ribbon Damage. Cracks, folds Pinches, scratches, etc…

Preliminary Information 42PQ30

Page 95

TCP 3.3V B+ Check

Checking IC221 for 3.3V, use center pin.

IC221

5V 3.3V 0V

3.3V

Warning: DO NOT attempt to run the set with the Heat Sink over the TCPs removed.

Check for 3.3V

P232

Top C231

Left

C206

3.3V in on Pins 49-50-51 3.3V in on Pins 49-50-51

Left X PWB

Right X PWB

Preliminary Information 42PQ30

Check for 3.3V

P331

Top C363

Left

C307

Page 96

TCP Visual Observation. Damaged TCP

Warning: DO NOT attempt to run the set with the Heat Sink over the TCPs removed. After a very short time, these ICs will begin to self destruct due to overheating.

This damaged TCP can, a) Cause the Power Supply to shutdown b) Generate abnormal vertical bars c) Cause the entire area driven by the TCP to be “All White” d) Cause the entire area driven by the TCP to be “All Black” e) Cause a “Single Line” defect

Preliminary Information 42PQ30

Page 97

X Drive Left Connector P211 Voltages and Resistance

Voltage and Diode Mode Measurements for the X Drive Board

P211 CONNECTOR "X Drive Left" to "X-Drive Right" P311

Diode ModeRun STBYLabelPin

GndGnd0VGnd1

GndGnd0VGnd2

Open15.4V0V15V3

n/an/a0Vn/c4

n/an/a0Vn/c5

* Note: This voltage will vary in accordance with Panel Label

Diode Mode Readings taken with all connectors Disconnected. DVM in Diode Mode.

Open*61.4V0VVPP/ER16

Open*61.4V0VVPP/ER17

Open*64.9V0VVA8

Preliminary Information 42PQ30

Page 98

X Drive Right Connector P311 Voltages and Resistance

Voltage and Diode Mode Measurements for the X Drive Board

P311 CONNECTOR "X Drive Right" to "X-Drive Left" P211

Diode ModeRun STBYLabelPin

GndGndGndGnd1

GndGndGndGnd2

Open15V0V15V3

n/an/a0Vn/c4

n/an/a0Vn/c5

* Note: This voltage will vary in accordance with Panel Label

Diode Mode Readings taken with all connectors Disconnected. DVM in Diode Mode.

Open*61.4V0VVPP/ER26

Open*61.4V0VVPP/ER27

Open*64.9V0VVA8

Preliminary Information 42PQ30

Page 99

X Drive Left and Right Connector P232 and P331

Voltage and Diode Mode Measurements for the X Drive Board

Voltage and Diode Mode Measurements for these connectors are difficult to read.

They are too close together for safe test.

The pins are also protected by a layer of tape to prevent the tab from being released causing separation from the Cable and the connector.

Preliminary Information 42PQ30

Page 100

Main PWB Troubleshooting

This Section of the Presentation will cover troubleshooting the Main Board. Upon completion of this Section the technician will have a better understanding of the operation of the circuit and will be able to locate voltage and resistance test points needed for troubleshooting and alignments.

• DC Voltage and Waveform Checks

• Resistance Measurements

Operating

Voltages

SMPS Supplied

Developed on the Main Board

100

5V Stand-By 12V 16V

3.3V (2)

2.5V

1.8V

Preliminary Information 42PQ30

LG 42PQ30 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

OUTLINE

ESD NOTICE

CONTACT INFORMATION

Basic Troubleshooting Steps

TCP Connector Removal

Panel Label Explanation

SMPS P/N EAY58349601 Check the silk screen label on the top center of the PWB of

TCP Testing