Just changed the toner cartridge on my Brother HL-1440 laser printer, it has separate toner and drum units, the toner is out but drum seems to work fine, but toward the end, it was also printing with vertical black streaks, so I figured the drum was dirty too. While I replaced the toner unit, I cleaned up the roller area of drum to brush off the excess toner collected there. Now the printer with the new toner works great, also the vertical streaks are gone too. However, now I'm getting horizontal bands (like smudges not lines) on the print out, about 3 bands on a single page, each is a few inches apart (just imagine 3 hole punched paper, the bands more or less correspond to where the holes are). Any idea what's causing it? I wonder if I should take out the drum unit and clean it up.