This is an actual photo of my TV rather than someone else's photo who had the same issue that was posted on another forum, however they did not any responce to their issue.

I purchased a used Samsung TV model UA65JS9000W recently knowing it had an issue with the screen. When switched on the picture was bright both sides of the screen but a little darker in the middle of the screen. Thinking this was the back lights (side mounted LCD strips) I replaced these, however the issue is still there. I am now thinking it may be a TCOM issue, but am not sure, any advice on this would be appreciated. Also whilst changing out the back lights I noticed the the thick clear plastic sheet (maybe 1.5 to 2mm thick) below the diffusers there is cracking (up to 75mm) on the sides and...