How to fix all screen vertical color lines in the screen?

Prem Bhandari  this could be a bad T-con board, bad main board, bad LVDS cables or even a bad panel. Remove the back cover from your TV and take a look at the cables first. Make sure they are properly connected, no corrosion etc. After that check the boards for obvious damage. Post some good pictures of your boards etc. with your Question so that we can see what you see. I’d start with a T-con board and work my way up from there. At least that way you will have a known-well starting point. Adding images to an existing question