Tuesday, August 30, 2016

LG 32LA66 series LED LCD TV – Troubleshooting method - Screen defects - Line fault

Video error – No video/Normal audio
Check the white balance value.
Entry method
Press ADJ button on the remote controller for adjustment.
Enter into the white balance item [10]
After recording the R,G,B [Gain Cut] value of color Temp [Cool/Medium/warm], re-enter the value after replacing the Main Board.
Click on the pictures to zoom in
Video error – No video/audio
Check the DC 24V, 12V, 3.5V
Video error – video lag/stop
Check the Tuner input signal strength.
Menu > support > signal test > select channel.
When the signal is strong, use the attenuator [-10dB, -15dB, -20dB etc.]
Tuner checking part.
Check the signal strength or check whether the screen is normal when the external device is connected.
After measuring each voltage from the power supply, finally replace the main board.
LCD TV version checking method.  [Checking method for remote controller adjustment]
Press the In-Start with the remote controller for adjustment.
Video error – color error
Adjustment Test Pattern – ADJ key on the adjust remote controller
Can view 6 types of patterns using the ADJ key.
Checking item:
1 Defective pixel
2 Residual image.
3 Module error [add-bar, scan bar]
4 video error [classification of module or main B/D]
On-screen defects
No power troubleshooting:  For 10 models, there is no voltage out for standby purpose.  When standby, only 3.5V is normally ON.
Power error: Off when ON/ Off while viewing
Power off mode; checking method
Press the In-Start button of the remote controller for adjustment.
Check the entry into adjustment item – 3
Audio error: No audio-Normal video
Press the menu button on the remote controller.
Select “Sound” function of the Menu.
Change TV sound out to TV speaker.
Voltage and speaker checking method; when there is no audio.
Check the contact condition of the 24V connector of the Main board.
Measure the 24V input voltage supplied from Power Board.  If there is no input, remove and check the connector.
Connect the tester RX1 to the speaker terminal and if you hear a Chick Chick sound when you touch the GND and output terminal, the speaker is normal.  If not, it is damaged.
Remote control operation checking method.
Check the IR cable condition between IR and the Main board.
Check the standby 3.5V on the terminal 4.
When checking the pre-amp when the power On condition, it is normal when the Analog tester needle moves slowly, and defective when it does not move at all.
V-Com adjustment [Flicker]
Case-1
LCD module change.
T’Con board change.
Adjust sequence
Press the ADJ key.
Select V-Com.
As pushing the right or the left button on the remote controller, and find the V-Com value, which is no or minimized the Flicker. [if there is no flicker at default value, press the exit key and finish the V-Com adjustment]
Push the OK key to store the value.  Then the message “Saving OK” will pop out.
Press the exit key to finish the V-Com adjustment.