Black streak down side of paper mod.pc-980 - Canon PC-980 Color Copier

SOURCE: I have a PC 25 copier. I am getting black streaks

Run a copy and shut the machine off when the copy is half way through. Open the machine up and remove the toner cartridge. Turn it over and slide open the flap that covers the drum. If you see toner streaks on the drum surface similar to what you see on the page you have a defective toner cartridge. Most likely the toner you bought is remanufactured as this machine is very old. Maybe you can return it for another.

Testimonial: "Thanks. Fortunately I kept the receipt for the cartridge - just bought it in August."

SOURCE: I have a Canon iR1024A that is leaving black

If you have changed the drum then probably your fixing film was torn. Check if the black streaks on paper is erasable (not fixed on the paper). Check also for signs of film (gray on one side and brown on the other very thin plastic-like material) falling out from your fixing assembly (if you open the left side cover with caution sign the hot portion area).