My Laser Printer Streaks on Output

Just about every component in a laser printer can cause streaks in its output. Some streaks are black, some are blurry and others come in the form of faded areas. While there are many different causes for stripes, the way that the stripe looks is frequently an indicator of the problem that your printer is having.

Sharp Black Streaks

If your print out has one or more sharp black vertical stripes running down some or all of the page, your laser printer's drum is failing or damaged. The drum picks up toner from the cartridge in areas where it gets charged by the printer's laser. It then deposits the toner on the paper. Toner can stick to a damaged drum even if it isn't supposed to and get transferred as a crisp black vertical stripe. Whether your drum is part of your cartridge or a separate device that's sometimes called an "imaging unit," replacing it should fix the problem.

Smeared Black Streaks

On the way out of your laser printer, the printed page passes through a fuser. The fuser has hot rollers that melt the toner onto the paper. If the fuser is dirty or damaged, it will also cause streaks on your printed output. Instead of causing a crisp stripe, though, the stripe will be somewhat blurry. If you're comfortable working on the inside of your laser printer, let your fuser cool down, and then clean it with a lint-free cloth and pure alcohol.

Faded Light Streaks

If your printouts have vertical streaks or blobs that are faded out, it's a sign that your toner cartridge is nearly empty, so replacing it will fix the problem. You can sometimes squeeze a little bit more life out of it, though, by removing it from your printer and shaking it back and forth a few times. This may loosen up some more toner.

Vertical White Areas

If you have vertical white areas that don't go away when you shake your toner cartridge or replace it, your printer may have dirty corona wires. The corona wires reset the drum's charge and, if they're coated in toner dust, they won't work properly. They are very fragile, so if you choose to clean them yourself, be as gentle as possible.