8 years PILOT 37" LCD TV displays thick vertical gray scale lines

My parents' 8 years PILOT 37" LCD TV displays thick vertical gray scale lines.

It happened 3 weeks ago, suddenly, the picture became gray, the sound kept on for a while and then disappeared.

Exact model : PIL3700CH (pic 3)

Observations :

1. When I connect it to the electricity - the red led outside of the tv is on.

2. When I turn it on (using the remote control or the on button) - the green led outside the TV is on.
then, the screen display is all gray (pic 1), and then it stables at these thick vertical gray lines (pic 2).

pic 1 :
http://tinypic.com/r/2nvb3pg/9

pic 2 :
http://tinypic.com/r/fo1xdy/9

pic 3 :
http://tinypic.com/r/24pkiki/9

3. when I opened the back cover - I did not notice any blown capacitor, nothing seems or smells burnt.

4. I have googled a lot, and now I assume that the fastest solution will be replacing one of the electronic boards (T-con / main / power / inverter ).

but I don't know to relate the symptoms to the right board failure.

Does anybody know this issue and can advice please ?

Thanks,

Doron