Being on storage for so long - you might have troubles unclogging the print heads.
Then - this "encoder strip" - it is used to track head' position along the page. If it has spots (as you say, I don't have your printer to see it internal workings), then print head will be lost across the page, and most probably will trigger an error.
A solution: Recycle it properly (not in your trash bin). I don't think you can get spares for ten-years old printer which used to cost $100 at introduction.