How can I fix a cannon np 6221 copier?

I have acquired a Cannon np 6221copier from a company that went out of business. It works good accept the copy has black lines coming across the copies. There appears to be a build of toner on a red roller next to the toner cartridge. I have wiped this roller down but it still keeps getting a build up of toner on it so all of my copies comes out with black lines. How can I prevent the build up on the roller?