When copying a page of print I get 2/3 lines mid of pg,no image

I do not have this connected to our computer system. I tried this out, I put a page of print on the glass to copy. I got 2 or 3 black lines mid page along the print path and no image. I then blew it out with canned "air" checked out the roller ... I thought a piece of paper had broken off and got caught. I emptied out the used toner reservoir (sometimes that messes up sensors). retried same results. I'm not getting a code error the printer thinks it's doing fine.