Mitsubishi VS-50707

Hello, For about 3 months my projection tv Mitsubishi VS-50707 image have been distorted. Scrambled horizontal curved lines all across of screen. At first the image would be distorted as soon as the tv was turned on but after 45 minutes to a hour the image would go back to normal. For the past few weeks the image still scrambles as first described but every once in while it shrinks horizontally to a total display of about 20 inches, eventually going back the the full scrambled screen image and does not go back to normal at all. Finally, I placed a service call to Sears. The technician told me that it had something to do with the deflection board and that this job would run for about $600. My concern is: Would it be worthy to fix an 8 year old tv? is this price Accurate? and is it something I could probably fix myself? being that I'm tech oriented. I found the deflection board diagram on the internet. Is there any way, you can tell me which part can be causing this problem. Any comments or assistance will be greatly appreciated.