I have a 2 year old Sony flat screen TV and for most of the time I've had it there has been a small grey bit near the bottom of the left hand side. I've never bothered to clean it off. Today I have looked up how to clean it I've used some spray for cleaning monitors on a micro fiber cloth. It was still there. So I damped the cloth and put a very small bit of washing up liquid on it and cleaned it with that. It was still there again. It's not too bad really but when the TV is showing something white you can see it. Am I stuck with this as I've left it to long to do anything about it or is there something else I can do? Thanks.

It could be 'clouding' which many LCD's can suffer from,or could be a darker area that I've suffered with one of my PC monitors (I think it's where the sandwiched layers of the screen have got pressed together)

Or it could be an external stain but if you can't clean it off then it might be behind the front surface which means probably not much you can do about it.

I did read about some Sony LCD's owners solving irregular screen problems like clouding by carefully unscrewing all the case screws around the edge and then tightening them up again carefully, apparently if a screen is overtightened or unevenly screwed together it can distort the LCD panel causing issues.... do at your own risk of course! I recall reading it on the AVforums a couple years ago.

Hi there, I was in a clients house last week and he had a 40" pannasonic on his wall, I noticed that most of the screen was cloudy or blurred looking from the bottom until 2 thirds up but mainly in the middle,I asked what was wrong and he said it was about 5yrs old andan engineer was coming to do a factory reset! I doubt this would have worked.

Maybe due to the backlight on its way out. It is unlikely to be screws being over tight, cause the symptoms would have been present from the day of purchase.

Thanks all I think this grey mark has been on the TV since I got it. it's not to bad only when the screen goes light coloured or white. And I can't clean it off so it must be internal. Sounds a bit drastic unscrewing the TV so will just put up with it. Don't think it's clouding as you don't see it when the screen is black just when it's light coloured or white. And when I clean it that bit seems to show up like I'm putting a lot of pressure on it but I'm not.

It could well be dust or dirt inside the screen, LCD panels aren't sealed - it's particularly 'common' if anyone smokes near the TV, or you have a coal or gas fire.