I also have a Sharp xv-z9000 that developed some spots on the image. I thought they were dust specks and sent it in for repair to Frostline of Chicago. Turned out the spots were caused by pits in the internal light optics and were not repairable. The projector still works but the blemishes on the image (it is afterall a ten year old projector) were too much for me to stand so I upgraded to the new Sharp xv-z30000. I love this new machine; image is terrfific particularly if you are coming from ten-year old technology.
It you want I can send you repair info for Frostline; they seems quite competent and charges were resonable.
Good luck. BTW, I love that old machine; it served excellently for ten years.