Panasonic Viera TH-42PX75U Quick start guide

Model : TH
Model : TH- -42PX75U 42PX75U
TH
TH- -50PX75U 50PX75U
TH
TH- -42PX77U 42PX77U
TH
TH- -50PX77U 50PX77U
Technical Guide
Technical Guide
Plasma
Plasma
(GPH10DU Chassis)
(GPH10DU Chassis)
Troubleshooting Handbook
Troubleshooting Handbook
Panasonic Services Company
National Training

Prepared by
Panasonic Service and Technology Company
National Training
Copyright © 2007 by Panasonic Services Company
All rights reserved. Unauthorized copying and distribution is a violation of law.
Warning
This service information is designed for experienced repair technicians only and is not designed for use by the
general public. It does not contain warnings or cautions to advise non-technical individuals of potential dangers
in attempting to service a product. Products powered by electricity should be serviced or repaired only by
experienced professional technicians. Any attempt to service or repair the product or products dealt with in this
service information by anyone else could result in serious injury or death.
!

Table of Contents
3
Subject Page
No Picture\No OSD 24
No Sound (TH-42PX600U) 25
Troubleshooting for Picture Problems 27
Diagnostic Method for Troubleshooting PDP
Television 28
Diagnosis by Test Pattern When OSD is Available 29
Diagnosis by Removing the D5 Connector 30
Troubleshooting for Picture Trouble 31
Diagnosis for Picture Problem (All Over the Screen) 32~35
Diagnosis of Vertical Line Problem 36
Picture Trouble at Upper or Lower half 37
Picture Trouble at Right or Left half (50 Inch) 38
Picture Trouble at Right or Left half (42/37 Inch) 39
Picture Trouble in 50 Inch Models 40
Picture Trouble all Over the Screen 41
Examples of Symptoms and Remedies 42~48
Reset and Self-check Procedure 49
Driver Setup Adjustment 51~52
Board Layout and Part Numbers 53~56
Subject Page
Troubleshooting Shutdown Problems 5
Power LED’s Response to Shutdown Operation 6
LED blinks 1 time 7
LED blinks 2 times 8
LED blinks 3 times 9
LED blinks 4 times 10
LED blinks 5 times (Quick Troubleshooting) 11
LED blinks 5 times 12
LED blinks 6 times 13-14
LED blinks 7 times 15
LED blinks 8 times 16
LED blinks 9 times 17
LED blinks 10 times before pressing the power button 18
LED blinks 10 times after pressing the power button 19
LED blinks 12 times 20
Dead part I 21
Dead part II 22
No Picture from one or all inputs (OSD and Sound OK) 23

Introduction
<Introduction>
1. Basic concept of how to determine the defective board
1) Verification of voltages
Normally, when there is a power problem, shutdown occurs immediately.
So, to resolve a power problem, voltage checks are necessary before shutdown.
2) Check if the power comes up after disconnecting the suspected board.
If power comes up (*) after disconnecting a board, the board is defective.
(*) “Power comes up” equals “no shutdown”.
2. Troubleshooting Video and Audio problems
3. Examples of video problems
4. Adjustment after PCB exchange
1) After exchanging the following boards, voltage adjustment is required.
P board, SC board, SS board => Please refer to the “Service Manual”.
4

Troubleshooting Shutdown Problems
5

Power LED’s Response to Shutdown Operation
Once
3.0sec (interval) Light
No Light
LED
Blinking
times Contents Check Point
2
3
4
5
6
8
<Check point>
1
9
7
12
10
15V line abnormality
3.3V line abnormality
Power Supply abnormality
5V line abnormality
Scan Driver (1)
abnormality/DRV_RST
Sustain Driver abnormality
STB5V sense time out
Panel Status abnormality
Scan Driver (2) abnormality
Voltage for sound abnormality
REG. voltage abnormality
D Board (15V SOS)
D Board (3.3V SOS)
P Board (Power SOS)
D Board (5V SOS)
SC,SU,SD Board (SC Energy recovery circuit)
C and D Boards Connections
SS Board (SS Energy recovery circuit)/Panel
A Board
D Board (Panel Status DET)
SC,SU,SD Board (SC Floating voltage area)
A Board (Sound SOS), C boards connections
A Board (A SOS, Tuner SOS)/SC/SS
<LED Blinking timing>
6

LED blinks 1 time
<Trouble Mode and Defective Board>
Trouble Mode
Communication Error
Defective Board
A Board
<How to find the defective boards>
The A board is defective.
To confirm this, unplug
the TV and disconnect
connectors A5, A6, and
A7 from the A board.
The TV should turn on
automatically and display
a white screen.
Warning: Disconnect AC Power prior to
making any disconnection or
connection.
7
Note: CN = Connector
A5, A6, and A7
location

LED blinks 2 times
<Trouble Mode and Defective Board>
Trouble Mode
15V down SOS
Defective Board (Possibility)
P, D, A, SC, SS Board (P > A, D, SC, SS)
<How to find the defective boards>
SC Board
D Board
No
Turn the unit on.
Does the power LED
stay on?
Unplug the TV, reconnect CN A5, A6, and A7 and
disconnect CN SC20 and SC2. To isolate the SC
board.
Unplug the TV, reconnect SC20 and SC2 and disconnect CN P12,
SS11, and SS23 (*1) to isolate the SS board. Remove the jumper at
CN SS34 and install it across pin 8 and 10 of connector P12.
SS Board
No
Turn the unit on.
Does the power LED
stay on?
Yes
Warning: Disconnect AC Power prior to
making any disconnection or
connection.
8
(*1) = The reference number of
the sustain data connector is
different in some of the models:
TH-42PX75U = SS23
TH-42PX77U = SS23
TH-50PX75U = SS33
TH-50PX77U = SS33
Unplug the TV,
Reconnect CN P12, SS11,
And SS23 (*1). Turn the unit on.
Is there 15V output at
CN P25 pin 1 or 2
before the TV
shuts down ?
D Board
Yes
No
P Board
Unplug the TV.
Disconnect CN P25. Is pin 1
or 2 of the CN P25 shorted to
GND?
Yes
Yes
Disconnect CN A5, A6,
and A7 on the A board. Does
the TV turn on by itself with
a white screen? A Board
Yes
No
Note: CN = Connector
No

LED blinks 3 times
<Trouble Mode and Defective Board>
Trouble Mode
3.3V down SOS
Defective Board
D Board
<How to find the defective boards>
The D board is defective.
Warning: Disconnect AC Power prior to
making any disconnection or
connection.
9
Note: CN = Connector

LED blinks 4 times
<Trouble Mode and Defective Board>
Trouble Mode
Power Supply SOS
Defective Board
Primarily P board or possible D board
<How to find the defective boards>
D Board
Turn the unit on.
Is pin 12 of CN P25 of
the P board high
before shutdown?
P Board
Yes
No
Warning: Disconnect AC Power prior to
making any disconnection or
connection.
10
Note: CN = Connector

LED blinks 5 times (Quick Troubleshooting)
<Trouble Mode and Defective Board>
Trouble Mode
5V SOS
Defective Board
D, P, C, SC, SS board or Panel (DDIC)*1
<How to find the defective boards>
Is there a short to ground?
Disconnect CN P12
of the power supply board. Measure the
resistance of pin 1 of the lead cable to ground.
Yes
Warning: Disconnect AC Power prior to
making any disconnection or
connection.
11
(*1) = Data Driver IC
Proceed to more extensive troubleshooting of
the pages that follow.
Panel
No
Note: CN = Connector

LED blinks 5 times
<Trouble Mode and Defective Board>
Trouble Mode
5V SOS
Defective Board
D, P, C, SC, SS board or Panel
<How to find the defective boards>
No
No
Connect SS23 (*1).
Disconnect CN D31and D32
on the D board. Is pin 5of CN P25
shorted
to GND?
Connect D31
and leave D32 disconnected.
Is pin 5 of CN P25 shorted
to GND?
Yes
No
Yes
No
D Board
Disconnect CB1-CB4.
Is pin 5 of CN P25 shorted
to GND?
Yes
No
C1 Board Panel
Disconnect D31.
Connect D32.
Is pin 5 CN P25 shorted
to GND?
Yes
No
Disconnect CB5-CB8.
Is pin 5 of CN P25 shorted
to GND?
Yes
No
C2 Board Panel
Connect
CN SC20. Disconnect
CN SS23 (*1) on the SS board.
Turn on the unit. Does the power
LED
Stay on?
SS Board
Yes
Disconnect
CN SC20 on the SC board. Turn
on the unit. Does the power LED
stay on?
SC Board
Disconnect
CN P25. Is pin 5 of the
socket P25 shorted
to GND?
P Board
Yes
No
P Board
Warning: Disconnect AC Power prior to
making any disconnection or
connection.
12
Yes
(*1) = The reference number of
the sustain data connector is
different in some of the models:
TH-42PX75U = SS23
TH-42PX77U = SS23
TH-50PX75U = SS33
TH-50PX77U = SS33
Note: CN = Connector

LED blinks 6 times
<Trouble Mode and Defective Board>
Trouble Mode
SC Energy Recovery SOS
Defective Board (Possibility)
SC, SS, D, P Board (SC > SS, D, P )
<How to find the defective boards>
D Board
P Board
Connect CN P12, SS11, SS34, and SS23(*3). Remove the A
board block assembly to gain access to the D and C boards.
(Remove 4 screws and 7 connectors)
SC Board
Yes
No
No
(*1) VSUS about 180V (Accurate voltage is provided on the Panel
Label)
CAUTION: Before connecting P2 or P11, discharge is necessary to
prevent potential shock caused by VSUS.
(*2) Place a jumper across pin 8 and 10 of connector P12. The unit will
not enter the standby mode without the jumper.
Warning: Disconnect AC Power prior to
making any disconnection or
connection.
Disconnect
connectors SC2, and
SC20 from the SC
board. Turn the TV on.
Does the TV power up
and
stay on?
SS Board
Yes
Connect
SC2 and
SC20. Disconnect
CN P12(*2) from the P board
and SS11, SS34, and SS23 (*3) from
the SS board. Place the jumper from
SS34 between pins 8 and 10 of
P12. Turn the TV on. Does
The TV power up
and stay on?
No
13
(*3) = The reference
number of the sustain
data connector is different
in some of the models:
TH-42PX75U = SS23
TH-42PX77U = SS23
TH-50PX75U = SS33
TH-50PX77U = SS33
No
Does the P board
output 15V at pin 7 of
P7 and Vsus at pin 1
of P2 before the TV
shuts down?
Yes
Note: CN = Connector
Ground the base of Q302 (Fig. 1 next pg) on the D board and turn the power on
Does the TV stay on?
Reseat the ribbon cables between
the D and the C boards. Also reseat
the cables between the C boards.
(See figure 2 on the next page
Yes

LED blinks 6 times
<Trouble Mode and Defective Board>
Trouble Mode
SC Energy Recovery SOS
Defective Board (Possibility)
SC, SS, D, P Board (SC > SS, D, P )
Warning: Disconnect AC Power prior to
making any disconnection or
connection.
14
Figure 1 Figure 2

LED blinks 7 times
<Trouble Mode and Defective Board>
<How to find the defective boards>
Trouble Mode
SC Floating voltage SOS
Defective Board (possibility)
SC, SU, SD, P board (SC,SU,SD>D,P)
SS Board
P Board
Disconnect
the connectors SC2,
and SC20 from the SC
board. Turn the TV on.
Does the TV power up
and
stay on?
Turn the TV on.
Does 15Vdc appear
at pin 1 of CN P25 on the
P board before the unit
shuts down?
Turn the TV on.
Does VSUS(*1)
voltage appear at pin 1 of
CN P2 of the P board
before shutdown?
Connect
the connectors SC2(*2),
and SC20 to the SC board.
Remove the SU board.
Turn the TV on. Does the
TV power up
and stay on?
SU Board
Yes
No
Yes
No
Yes
No
Yes
No
Make sure the connectors P2/SC2, SC20/D20 are not loose and seated properly.
Note: CN = Connector
Warning: Disconnect AC Power prior to
making any disconnection or
connection.
Install
the SU board and
Remove the SD board.
Turn the TV on. Does
it power up
and stay on?
SD Board
Yes
No
P Board
SC Board.
NOTE: If the SC board
does not fix the
problem, replace the D
board.
(*1) VSUS about 180V
(Accurate voltage is
provided on the Panel
Label)
(*2) CAUTION:
Before connecting
P2/SC2 or P11/SS11,
discharge is necessary
to prevent potential
shock caused by
VSUS.
15

LED blinks 8 times
<Trouble Mode and Defective Board>
Trouble Mode
SS Energy recovery SOS/Panel
Defective Board (possibility)
SS, SC, D, P board (SS>SC,D,P)/PDP
(*1) Place a jumper across pin 8 and 10 of
connector P12. The unit will not enter the standby
mode without the jumper.
(*3) VSUS about 180V (Accurate voltage is written
on the Panel Label of the chassis)
CAUTION : To avoid potential shock from the VSUS
voltage, discharge the connectors SC2 or SS11
before reconnecting them into their respective
socket.
(*4) If the power LED continues to blink after
replacing the SS board, change the D board.
SC Board
P Board
Turn the TV on.
Is the VSUS(*3) input at
pin 1 of CN P11 present
before Shutdown?
No No
Yes
No
D Board
SS Board
(*4)
Yes
Warning: Disconnect AC Power prior to
making any disconnection or
connection.
Disconnect
CN SS11 and SS23 (*2)
from the SS board and
CN P12 (*1) from the P
board. Turn the TV on.
Does the TV power up
and stay on?
Disconnect
CN SC2, and SC20
from the SC board.
Turn the TV on. Does
the TV power up and
stay on?
16
Yes
(*2) = The reference
number of the sustain
data connector is
different in some of the
models:
TH-42PX75U = SS23
TH-42PX77U = SS23
TH-50PX75U = SS33
TH-50PX77U = SS33
Is the collector of Q251 or the
anode of D255 on the SS board
high.
Panel
SS Board
SS34 SS34
Q551 and D255 Location.
Yes
No

LED blinks 9 times
<Trouble Mode and Defective Board>
Trouble Mode
Panel Status
Defective Board
D Board
<How to find the defective boards>
In this case, only the D board is defective.
Warning: Disconnect AC Power prior to
making any disconnection or
connection.
17

LED blinks 10 times before pressing the power button
<Trouble Mode and Defective Board>
Trouble Mode
SUB 5V SOS, Main 3.3V SOS
DTV 9V SOS, Tuner Power SOS
Defective Board
P, A Board
<How to find the defective board(s)>
Disconnect connectors A5, A6, and A7 on the A board and plug
the TV into the AC line.
Does the TV turn on by
itself with a white screen
and the power LED is off?
No
Yes
A Board
P Board.
Warning: Disconnect AC Power prior to
making any disconnection or
connection.
18
Connectors A7, A6,
and A5 location.

LED blinks 10 times after pressing the power button
<Trouble Mode and Defective Board>
Trouble Mode
SUB 5V SOS, Main 3.3V SOS
DTV 9V SOS, Tuner Power SOS
Defective Board
P, A, SC,SS Board
<How to find the defective board(s)>
Disconnect connectors A5, A6, and A7 on the A board and plug
the TV into the AC line.
Does the TV turn on by
itself with a white screen
and the power LED is off?
No
Yes
A Board
Warning: Disconnect AC Power prior to
making any disconnection or
connection.
19
Unplug the TV and connect CN A5,
CN A6, and CN A7. Disconnect CN
SC2(*1), and SC20 of the SC board.
Plug the unit in.
Does the power LED
stay on when the TV is
turned on?
Yes SC
Board
No
Unplug the TV and re-connect CN SC2(*1),
and SC20 of the SC board. Disconnect CN
SS11(*1), SS23(*2), and SS34 of the SS
board and CN P12 of the P board. Install the
jumper from SS34 between pin 8 and 10 of
CN P12. Plug the unit in.
(*2) = The reference number
of the sustain data
connector is different in
some of the models:
TH-42PX75U = SS23
TH-42PX77U = SS23
TH-50PX75U = SS33
TH-50PX77U = SS33
(*1) = To avoid potential
shock from the VSUS voltage,
discharge the connectors
SC2 or SS11 before
reconnecting them into their
respective socket.
Does the power LED stay on when
the TV is turned on? Yes SS
Board
No
P Board
Note: CN = Connector

LED blinks 12 times
<Trouble Mode and Defective Board>
Trouble Mode
Sound SOS
Defective Board (Possibility)
Speakers, A Board
<How to find the defective boards>
Disconnect the connectors A5, A6,
and A7 on the P board.
Check the speakers.
Yes
No
Does the
TV turn on by itself
with a white screen. Reconnect CN A5, A6, and
A7. Disconnect CN SC2(*1),
and SC20 of the SC board.
Turn the unit on.
Does the power
LED stay on?
SC Board
Yes
No
Disconnect CN SS11(*1),
SS12 (*2) and SS23 (*3)
of the SS board. Turn the
unit on.
Does
the power LED stay
on?
SS Board
No Do pins 1
and 2 of CN P25
output 15V before
the unit shuts
down?
P Board
No
D Board
Yes
Warning: Disconnect AC Power
prior to making any disconnection
or connection.
20
(*1) = To avoid potential shock from the VSUS voltage, discharge the
connectors SC2 or SS11 before reconnecting them into their respective socket.
(*3) = The reference number of the sustain
data connector is different in some of the
models:
TH-42PX75U = SS23
TH-42PX77U = SS23
TH-50PX75U = SS33
TH-50PX77U = SS33
(*2) = Remove the jumper at CN SS34 and
install it across pin 8 and 10 of connector P12.
A Board
Yes
No
Reconnect A5, A6, and
A7 and disconnect the
speakers. Turn the power
on. Does the TV stay on?
Yes