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basic_troubleshooting_pdp_102
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Philips basic_troubleshooting_pdp_102 Datasheet

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Service Training
Service Training
BASICS of PDP Trouble shooting
L. van der Niet Philips CE / Euroservice PDP repair part 2 March 2007
Basics of PDP Trouble shooting ––
Basics of PDP Trouble shooting
Target Audience
Target Audience
This module is intended for Service Engineers
This module is intended for Service Engineers
repairing Plasma Television.
repairing Plasma Television.
Objective
Objective
This module provides a basic knowledge on how to
This module provides a basic knowledge on how to
diagnose and trouble shoot Plasma Display panels
diagnose and trouble shoot Plasma Display panels
in general. It is not model specific. This knowledge
in general. It is not model specific. This knowledge
enables the learner to better recognize major fault
enables the learner to better recognize major fault
symptoms of PDP’s and to identify the parts that
symptoms of PDP’s and to identify the parts that
most probably cause the problem.
most probably cause the problem.
Prerequisites
Students should have an understanding of the Basics of Television and finished the module PDP Basics.
An Introduction
An Introduction
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MAIN
MAIN
TOPICS
TOPICS
Screen faults and other symptoms
PCB functions and waveforms
Suggested repair actions
INTRODUCTION
INTRODUCTION
Trouble shooting on the PLASMA DISPLAY Panel is done on board level. This training module shows a number of common faults that can be encountered in all PDP Televisions.
Plasma panel faults Scan & Sustain board faults Common & Sustain board Address driver board faults Control Logic board faults Power Supply Unit
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More product specific faults are treated in separate service training modules.
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Panel Error Examples and Solutions
Panel Error Examples and Solutions
Vertical line
Vertical black bar (1)
Vertical black bar (2)
Vertical lines
Flicker noise
Image retention, but no image sticking
Panel Error Examples and Solutions
Panel Error Examples and Solutions
Vertical line
Vertical black bar (1)
Vertical black bar (2)
Vertical lines
Flicker noise
Image retention, but no image sticking
Check the COF
1.Inspect 10 ohm resistors and drive IC’s
2.Inspect the film where the COF connects to the Address drive board
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3.Replace the Plasma panel
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Panel Error Examples and Solutions
Panel Error Examples and Solutions
Vertical line
Vertical black bar (1)
Vertical black bar (2)
Vertical lines
Flicker noise
Image retention, but no image sticking
Check the COF
1.Inspect 10 ohm resistors and drive IC’s
2.Inspect the film where the COF connects to the Address drive board
3.Replace the Plasma panel
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Panel Error Examples and Solutions
Panel Error Examples and Solutions
Vertical line
Vertical black bar (1)
Vertical black bar (2)
Vertical lines
Flicker noise
Image retention, but no image sticking
Check the COF
1.Inspect 10 ohm resistors and drive IC’s
2.Inspect the film where the COF connects to the Address drive board
3.Replace the Plasma panel
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Panel Error Examples and Solutions
Panel Error Examples and Solutions
Vertical line
Vertical black bar (1)
Vertical black bar (2)
Vertical lines
Flicker noise
Image retention, but no image sticking
Check the COF
2.Inspect the film where the COF connects to the Address drive board
3.Replace the Plasma panel
Panel Error Examples and Solutions
Panel Error Examples and Solutions
Vertical line
Vertical black bar (1)
Vertical black bar (2)
Vertical lines
Flicker noise
Image retention, but no image sticking
Replace the Control Board
1.Check if the screen retains outlines such as Teletext and/or menu’s
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2.Replace the control board
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Panel Error Examples and Solutions
Panel Error Examples and Solutions
Vertical line
Vertical black bar (1)
Vertical black bar (2)
Vertical lines
Flicker noise
Image retention (burn-in)
Replace the Control Board
1.Check if the screen retains outlines such as Teletext and/or menu’s
2.Replace the control board
PDP General Block Diagram
PDP General Block Diagram
Power Supply
Va
Vs
+5V
+15V
Vs
+5V
+15V
Vsc
Vsetup
Scan
sustain
driver
(Y-sus)
+5Vctrl
Plasma Panel
LVDS input
Scan Control
(Control Logic)
common
sustain
driver
(Z-sus)
Vs Vsetup Vsc
+5V
+15V
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+5V
+15V
Address driver
(X-sus)
Va
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Typical PDP board layout
Typical PDP board layout
Y-DRIVE
Y-DRIVE
Top
Top
Y-DRIVE
Y-DRIVE
Bottom
Bottom
Y-SUS
Y-SUS
X-LEFT
X-LEFT
PSU
Control
Control
or Logic
or Logic
Common
Common
Z-SUS
X-Right
X-Right
X- or
X- or
Z-SUS
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Control Logic Board
Control Logic Board
The Control Board receives the LVDS video signal from the Television part.
The control Board converts this LVDS signal into
Let’s first have a look at the Control Board
addressing and control signals for the other boards in the PDP.
Therefore the Control Board has connections to Address, Scan sustain and Common sustain boards.
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Control Board
Control Board
To Scan
LVDS input signal
Driver
YY--Driver
Addressing signal
to left board
MCM
Multi Chip Module
To
Common
Addressing signal
to right board
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Two Y-driver boards are located on the left-hand side (looking from the back) of the TV. Each is supporting half of the screen. The upper one the top half of the screen and the lower board the lower half.
The sustain and reset waveform from the Y-SUS board is passed on via the scan driver IC's on both Y-boards to the plasma panel. In case of a 42 inch screen, 8 scan driver IC's (4 on each Y-board) are needed to address every horizontal line (Y sustain electrode).
Next slide shows how the Y-waveform is built up
Y-driver
Y-SUS
Y-driver
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waveform
YY--waveform
Set-up Scan
Sustain
Set-up (or erase) phase Creating the wall-charge
Scan (or address) phase Addressing the sub-pixel to be fired
Sustain phase Generating visible light by addressed sub-pixel
Y driver Voltage levels
Y driver Voltage levels
Voltage level is critical to get a good picture.
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Vs is too low → Too dark picture
(The brightness of the picture will be too low)
Vs is too high
will become too bright (The brightness of the picture will be too high)
→ Black parts (e.g. shadows)
If Vsetup is not correct, it will result in flicker noise or solarization.
Flicker noise
Solarization
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Y board: Error Examples and Solutions
Y board: Error Examples and Solutions
No picture shown and flicker, wrong discharge (1) No picture shown and flicker, wrong discharge (2) Large black horizontal bar Horizontal line or lines Moving OSD "curtain" Picture is shown, but wrong discharge
Y board: Error Examples and Solutions
Y board: Error Examples and Solutions
No picture shown and flicker, wrong discharge (1)
No picture shown and flicker, wrong discharge (2) Large black horizontal bar Horizontal line or lines Moving OSD "curtain" Picture is shown, but wrong discharge
Replace the Y-board
1.The SUS-up and SUS­down diodes might be damaged (check with Ohm-meter)
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2.Replace the Y-board
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Y board: Error Examples and Solutions
Y board: Error Examples and Solutions
No picture shown and flicker, wrong discharge (1)
No picture shown and flicker, wrong discharge (2)
Large black horizontal bar Horizontal line or lines Moving OSD "curtain" Picture is shown, but wrong discharge
Replace the Y-board
1.Check and readjust voltage levels of Vs and Vsetup
2.Check if 15V to the Control board is present
3.Replace the Y-board
Y board: Error Examples and Solutions
Y board: Error Examples and Solutions
No picture shown and flicker, wrong discharge (1) No picture shown and flicker, wrong discharge (2)
Large black horizontal bar
Horizontal line or lines Moving OSD "curtain" Picture is shown, but wrong discharge
Replace the Y-board
1.Check the SCAN driver IC of the Y­driver board
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2.Check the connector
3.Replace the Y-board
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Y board: Error Examples and Solutions
Y board: Error Examples and Solutions
No picture shown and flicker, wrong discharge (1) No picture shown and flicker, wrong discharge (2) Large black horizontal bar
Horizontal line or lines
Moving OSD "curtain" Picture is shown, but wrong discharge
Replace the Y-board
1.The FPC on the Y­driver board is not well connected or polluted
2.Reposition and clean the FPC
3.If problem still exists then replace the Y-board
Y board: Error Examples and Solutions
Y board: Error Examples and Solutions
No picture shown and flicker, wrong discharge (1) No picture shown and flicker, wrong discharge (2) Large black horizontal bar Horizontal line or lines
Moving OSD "curtain"
Picture is shown, but wrong discharge
Replace the Y-board
1.The SUS-up and SUS­down diodes might be damaged (check with Ohm-meter)
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2.Replace the Y-board
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Y board: Error Examples and Solutions
Y board: Error Examples and Solutions
No picture shown and flicker, wrong discharge (1) No picture shown and flicker, wrong discharge (2) Large black horizontal bar Horizontal line or lines Moving OSD "curtain"
Picture is shown, but wrong discharge
Replace the Y-board
1.The SUS-up and SUS­down diodes might be damaged (check with Ohm-meter)
2.Replace the Y-board
Address (X) --
Address (X)
The X-board generates the address pulses during the scan phase.
The x-waveform is passed on to the plasma panel via Chips On Film (COF).
The X-board receives the information, about which pixel should be turned on and which should be off, from the control board.
board
board
Always handle the COF with extreme care. If the COF gets damaged, the whole plasma panel needs to be replaced !!!!
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board trouble shooting
XX--board trouble shooting
A problem with the X-board is recognized by vertical lines / bars on the screen.
Single line failures
One single line having a failure is related to the plasma panel itself and the panel has to be replaced.
Multiple line failures
With a multiple line failure, the problem is likely to be on the X-board, the connection between the X-board and the Control board, the Control board or the COF.
board: Error examples and Solution
XX--board: Error examples and Solution
Vertical bar or bars in part of screen
Replace the X-board
1.Check the signal cable from the control board to the X-board. If not correct replace the cable.
2.Check the 5V power (cable). If not correct change the power cable or board
3.If the problem still exists or cabling is OK, then replace the X-board
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Common sustain (Z)--
Common sustain (Z)
The Z-board provides the signal for the Z-electrodes in the sustain phase of the sub-pixel. During the scan period the signal is high and during the sustain period the signal is alternating on and off opposite to the Y-electrode. The Z-board is controlled by the Control board.
Be careful when replacing the Z-board. Just like the X and Y board the FPC, which is part of the plasma panel, must be handled with extreme care.
How to replace the Z-board
1. Unlock the connector
2. Pull out the FPC gently
Board
Board
board: Error examples and Solutions
ZZ--board: Error examples and Solutions
Picture is dark and has noise (wrong discharge)
Replace the Z-board
1.Check connectors and cables to the Z-board. If not correct replace them.
2.Check the input voltages on the Z-board. If not correct adjust them on the power board.
3.If the problem still exists, then replace the Z­board.
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Power Supply
Power Supply
AC / DC
changes the input AC voltage (100~240V) to DC voltage (380V)
DC / DC
generates a number of DC voltages from the DC 380V DC:
• Low voltages: Stand-By 5V, 5/12/15/30V
• High voltages: Va, Vs, Vset-up, -Vy, Vsc
a
s
set_up
sc
y
Typical voltage levels
Vsc
Vsc
Vsetup
Vsetup
Ve
--Ve
Vy
--Vy
~70 V Address Voltage V
~180 V Sustain Voltage V
~265 V Setup Voltage V
~120 V Scan Voltage V
~-75 VV
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PSU trouble shooting
PSU trouble shooting
The Plasma Display might have an auto-protection mechanism which shuts the panel down after some seconds, when there is something wrong in the set. This could be a wrong voltage level or no specific power level at. In case the status indicator LED returns to RED after a few seconds when switching the set on, then check if the following voltages are down:
Check Y-SUS, Z-SUS and PSU180V (Vs)
Check X-board75V (Va)
Check Y-SUS or PSU120V (Vsc)
Y-SUS or PSU240V (Vsetup)
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Power Supply error example
Power Supply error example
This is the result when the 15V drops under 14V
• Check the 15V from the Power Supply board
• Check for short circuits on the X-board
• Replace the Power Supply board or the X-board
Check--
Check
up Flowchart: Summary
up Flowchart: Summary
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End of Module
End of Module
Basic PDP Trouble shooting
Basic PDP Trouble shooting
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