Panasonic TX-42AR400 Service Manual ▷ View online
TX-42AR400
10
6 Troubleshooting Guide
Use the self-check function to test the unit.
1. Checking the IIC bus lines
2. Power LED Blinking timing
2. Power LED Blinking timing
6.1.
Check of the IIC bus lines
6.1.1.
How to access
6.1.2.
Self-check indication only
Produce TV reception screen, and while pressing [VOLUME ( - )] button on the main unit, press [OK] button on the remote control
for more than 3 seconds.
for more than 3 seconds.
6.1.3.
Self-check indication and forced to factory shipment setting
Produce TV reception screen, and while pressing [VOLUME ( - )] button on the main unit, press [MENU] button on the remote
control for more than 3 seconds.
control for more than 3 seconds.
6.1.4.
Exit
Disconnect the AC cord from wall outlet.
6.1.5.
Screen display
TX-42AR400
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6.2.
Power LED Blinking timing chart
1. Subject
Information of LED Flashing timing chart.
2. Contents
When an abnormality occurs, the protection circuit will operate and reset the unit to stand by mode. During this time, the
defective block can be identified by the number of blinking times of the Power LED on the front panel of the unit as follow:
defective block can be identified by the number of blinking times of the Power LED on the front panel of the unit as follow:
6.3.
Method of detecting SOS
1. BL_SOS
Detection beginning after one second pass from ‘BL_ON’=ON
2. TV_SOS
Detection beginning after one second pass from ‘AMP_SHUTDOWN’=ON
3. SOUND_SOS
Detection beginning ‘AMP_SHUTDOWN’=ON
Priority
Name
Factor
R_LED Blink
1
BL_SOS
SOS from PANEL inverter
1
2
TV_SOS
TCON power down
3
3
SOUND_SOS
SOS from audio AMP
9
TX-42AR400
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6.4.
LCD Panel test mode
Purpose:
To find the possible failure point where in LCD Panel or Printed Circuit Board when the abnormal picture is displayed.
How to Enter:
How to Enter:
While pressing [VOLUME ( - )] button of the main unit, press [OPTION] button of the remote control three times within 2
seconds.
How to Exit:
seconds.
How to Exit:
Disconnect AC plug from wall outlet.
How to confirm:
How to confirm:
If the abnormal picture is displayed, go into LCD Panel test mode to display the several test patterns.
And then, judge by the following method.
Still abnormal picture is displayed: The cause must be in LCD Panel.
Normal picture is displayed: The cause must be in A board.
Remarks:
And then, judge by the following method.
Still abnormal picture is displayed: The cause must be in LCD Panel.
Normal picture is displayed: The cause must be in A board.
Remarks:
The test pattern is created by the circuit in LCD Panel.
In LCD Panel test mode, this test pattern is displayed unaffected by signal processing for RF or input signal.
If the normal picture is displayed, LCD Panel must be okay and the cause of failure must be in A board.
In LCD Panel test mode, this test pattern is displayed unaffected by signal processing for RF or input signal.
If the normal picture is displayed, LCD Panel must be okay and the cause of failure must be in A board.
6.5.
No Power
First check point
There are following 2 states of No Power indication by power LED.
There are following 2 states of No Power indication by power LED.
1. No lit
2. Red is lit then turns red blinking a few seconds later. (See 6.2.)
2. Red is lit then turns red blinking a few seconds later. (See 6.2.)
TX-42AR400
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7 Disassembly and Assembly Instructions
7.1.
Speaker Fixing and Assembly
1. Fix speaker bracket at panel and screw.
2. Stick sponge at speaker and slot at speaker bracket.
2. Stick sponge at speaker and slot at speaker bracket.
NO
QTY
UOM
DESCRIPTION
REMARK
01
2
PC
SPEAKER UNIT
02
4
PC
SCREW (A3/P5/VESA4/MTL4/LBRD4/SP4)
06 ± 1 Kgf.cm
03
4
PC
SP BRACKET
04
4
PC
SP. SPONGE
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