Red Screen on Zenith rear projo

I have a 'Zenith pvy4665dt 46 inch big screen. It is about 10 years old. It developed a problem. A red or pink shadow appeared on the right side of the screen and moved left to cover the screen. It first happened a couple of times but now is perminate. I am not able to adjust it out. I checked the bard on the back of the red tube and did not find any burn or open resisters. I am unable to adjust the convergence horizontally. I can change boards, do some work on them etc. Anyone have any ideas???

Thanks