I am looking to dianose an ongoing and slowly progressive problem, I having with my Sony WEGA HDTV model KD-34BR970. When it is initially turned on, has 3 to 4 inch tall horizontal band across center of screen with distorted blurry lines. The problem resolves itself after a few minutes as the band narrows down to one line across the screen and disappears altogether and is picture perfect until the next time tv is turned off and then restarted. The problem has been gettting worse for the last year or so. I first noticed it when it the blurry band was less than an inch tall and disappeared in less than a minute. Now it takes up to 10 minutes to resolve itself. The set otherwise operates perfectly with consistant excellent vibrant HD clarity and color, once it has warmed up. Does anyone have a best guess what circuit is starting to fail and the difficulty and expense to repair?