Magnovox 9p5511c102 projection TV picture fades

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I own a Magnovox 9p5511c102 for about 10 years and about a month ago the picture started to fade and become blurry when I first turn it on. When the problem started, the picture would return to normal size and sharpness after 5 minutes of leaving the tv on. Now, a month later, it takes about 30 minutes for the picture to return to normal. I'm afraid the time will soon come that the picture will no longer return to normal. Is there something I can do to fix this problem? An adjustment maybe? The tv has never been repaired.