I have a 40 inch Samsung with regular dark patches (10 in total) in two columns of 5 on either side of the screen centre (See image).
These patches appear on any source including the no signal blue screen.
The patches are most noticeable on a bright uniform image.
TV is around 4 years old and cost over £1500 so I don't want it scrapped if possible!!

(The attached image has had the contrast/brightness edited to make the patches more visable)
Any help would be appreciated/