Why is my LCD TV picture faded grey , everything else is working fine.

Peter Assaly symptoms that you are describing could be caused by a bad T-con board. Possibly a fault on VGM which supplies the Gamma IC. I would look into replacing that since schematics are not easily found. Replacement vs Repair because of the lack of supporting schematics. the other issue here is that this "could" be an issue with the LCD driver boards on your panel. See if there are any components that look corroded, or otherwise damaged. Those boards are not replaceable by a DIY'er

you can always post some good images of all of your boards with your Question. That way we can see what you see and maybe find something that will be more helpful. iFixitでの質問に画像を追加する方法