Laser printer streaks and how to fix them

Last Updated on September 10, 2023 by Dave Farquhar

Laser printers tend to be fairly low-maintenance items. When they start printing streaks across your pages, that’s how you know it’s time for service. It doesn’t usually mean you need a new printer. In this blog post, I’ll tell you how to fix laser printer streaks.

Laser printer streaks usually mean the printer’s toner cartridge or drum unit has a problem. On some printers the drum unit is part of the toner cartridge, but on cheaper printers, it may be a separate piece.

Before I specialized in computer security for a living, I spent around 7 years handling printers, among other things. We had a maintenance contract to take care of major issues. But I was in charge of most of the day-to-day stuff when it came to printers.

I see far too many people throwing out perfectly good laser printers just because they don’t print properly. Here’s how to fix that problem.

Table of Contents

1. Checking the toner cartridge to fix laser printer streaks
2. Checking the drum
3. The drum wiper
4. What to do if your laser printer streaks with a new toner cartridge

Checking the toner cartridge to fix laser printer streaks

The simplest fix for laser printer streaks is checking the toner cartridge. If the cartridge is getting close to empty, the toner distribution inside could be uneven. Taking the cartridge out and shaking it back and forth can redistribute the toner so you can print well again, at least for a little while. If this fixes the problem, order a new cartridge, because you don’t have a lot of pages left in that cartridge. At home you might get by a month, but in a busy office, that cartridge may only last another day or so.

It can be hard to remember how old a cartridge is, so I like to write the date on a cartridge when I change it.

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Checking the drum

If that doesn’t work, check the drum. The drum gets hot, so turn the printer off and let it sit 15-30 minutes before you do this. On toner cartridges that contain a drum, there’s a spring loaded part that covers a long, green rotating drum that distributes the toner. On a properly functioning cartridge, the drum is pretty clean. If you open the spring loaded door and see an excessive amount of toner on the drum, that’s probably causing your streaks. You can clean the drum with a cotton swab with some isopropyl alcohol on it. There may be a gear on the outside of the cartridge you can turn to rotate the drum so you can change what area on the drum is exposed.

Don’t touch the drum with your fingers, because that will damage it.

After cleaning the drum, print a few pages containing just a single character (ideally something like a period, that doesn’t use much toner), to help get rid of the rest.

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The drum wiper

There’s a wiper on the drum that will eventually wear out. It can even degrade just while sitting around, but that takes decades. But on an older cartridge that’s been in use a while, the wiper can wear out from use, the same way your car’s windshield wipers do. If you’re constantly having to clean the drum, the cartridge needs replacement.

If your drum unit isn’t part of the toner cartridge, and you’ve never replaced it before, it’s time to replace it if you’re getting streaks. On cheaper printers, the drum unit is generally good for 2-5 toner cartridges, depending on how long the toner cartridges themselves last, and the nature of what you print. Big-box stores like Best Buy generally don’t have much selection of printer supplies, but the big office supply chains frequently will have them. If not, do a Google search on your make of printer and the words “drum unit” to find the part number and where to order it.

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What to do if your laser printer streaks with a new toner cartridge

Occasionally, you can buy a new (or more likely, remanufactured) toner cartridge that streaks from the get-go. That’s not a problem with your printer, it’s a problem with the cartridge. Some remanufacturers don’t replace the blade when they remanufacture. I’ve been using 4inkjets for the last 15 years and I recommend them. With random vendors on Ebay and Amazon, it was more like a 50/50 chance the cartridges were remanufactured properly.

The remanufactured cartridges from the major office supply store chains are fine too, so if you’re in a hurry, they’re a viable option. But 4inkjets is cheaper if you can wait for shipping.

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