Why the sudden darker image on the left side of the screen?

@mfm12 "little bit of a lag when I change channel ", " there was ghosting of the image." sounds like a defective T-Con board or a loose T-con to panel connecting cable. Unplug your set and remove the back cover. Check the boards for obvious damage like leaking or domed capacitors. Post some images of your boards with your question so that we can see what you see. For that use this guide. Also check all the cables to ensure they are properly seated. If none of that works, I'd suggest to replace the T-con board first. I am certain we can give you more information on how to do that if you can let us know the exact model of your TV.