Monday, January 11, 2016

PANASONIC TX-LR42U3 Service mode- Led blinking code – Voltage adjustments – LCD television Repair and service

Category: LCD Television Repair and Service 

Contents of this article 

  • How to enter to service mode 
  • Power Led blinking and causes 
  • Voltage chart 

PANASONIC TX-LR42U3

Service Mode
How to enter into Service Mode
While pressing [VOLUME ( - )] button of the main unit, press [INFO] button of the remote control three times within 2 seconds.
How to exit
Switch off the power with the [POWER] button on the main unit or the [POWER] button on the remote control.
SRV-TOOL
How to access
1. Select [SRV-TOOL] in Service Mode.
2. Press [OK] button on the remote control.
Display of SOS History
SOS History (Number of LED blinking ) indication.
From left side; Last SOS, before Last, three occurrence before, 2nd occurrence after shipment, 1st occurrence after shipment.
This indication except 2nd and 1st occurrence after shipment will be cleared by [Self-check indication and forced to factory shipment setting].
POWER ON TIME/COUNT
Note : To display TIME/COUNT menu, highlight position, then press MUTE for 3sec.
Time : Cumulative power on time, indicated hour : minute by decimal
Count : Number of ON times by decimal
Note : This indication will not be cleared by either of the self-checks or any other command.
Exit
1. Disconnect the AC cord from wall outlet.
Self Check Mode
1. Press the ‘MENU’ button (on the remote control) and the ‘VOL DOWN’ button on the LCD panel.
2. Press ON/OFF button on the panel to Exit.
Hotel Mode Adjustment
1. Press the ‘VOLUME DOWN’ button on the TV panel and simultaneously press the AV button on the remote control 3 times to
enter Hotel Mode.
2. Set Hotel mode ‘on/off’, then press ‘EXIT’ to come out.
Hotel Mode
Access command to the Hotel mode setup menu. In order to display the Hotel mode setup menu, please enter the following command (within 2 second). [TV] : Vol [Down] + [REMOTE] : INPUT (3 times).
To exit the Hotel mode setup menu
Disconnect AC power cord from wall outlet.
Troubleshooting Guide
Use the self-check function to test the unit.
1. Checking the IIC bus lines
2. Power LED Blinking timing
Check of the IIC bus lines
How to access
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.
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.
Exit
Disconnect the AC cord from wall outlet
Power LED Blinking
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:
Times
SOS
PCB NAME
1


BackLight_SOS


A-Board
P-Board
LCD Panel
3
SOS(Tuner_SOS)
A-Board
4
SUB12V_SENSE_SOS
A-Board
7
SUB3.3V_SENSE_SOS
A-Board
9

SOUND_SOS

A-Board
P-Board
10

ZWEI2_SOS

A-Board
LCD Panel
12
BackEnd(sLD)_SOS
A-Board
13
EMERGENCY_SOS
A-Board
14
ROM_SOS
A-Board
Voltage chart of A-board
Set A-Board to a dummy set and check the satisfaction with the specified voltage as following table
VOLTAGE
TEST POINT
SPECIFICATION
SUB3.3V
TP8615
3.21 - 3.45 V
SUB1.5V
TP8101
1.47 - 1.56 V
SUB1.2V
TP8100
1.26 - 1.33 V
SUB5V
TP0910
4.8 - 5.2 V
Voltage chart of P-board
Set P-Board to a dummy set and check the satisfaction with the specified voltage as following table.
VOLTAGE
TEST POINT
SPECIFICATION
PFC390V

+TP811, TP812
390 ± 15V

+TP813, TP814
PVT16V

+TP818, TP819
15.6 ± 1.5V

+TP828, TP827

24V
+TP830, TP829

24 ± 2V
+TP828, TP827


STBY6V
+TP816, TP817


5.8 ± 0.8V
+TP828, TP827