Question LG 55LS4500 - Vertical Lines

[letmefixit]

I have the LG 55LS4500 TV. When I switch on, the power LED blinks 3 times and after that I see vertical lines from end to end. I replacement the t-con board, but its not resolved. All cables are secure and I dont see any change in the screen if I tap or press the cables. What could be the issue ?

How do I check this t-con board for voltage correctness ? 6870C-0421A

t-con board

Screen looks like this screen

 

[letmefixit]

This is the voltage on the t-con board.

fuse : 12v
VDD : 16.9v
VGH : 26.7v
VGL : -6.9v
VCOM : 7.9v

thanks