Diagnosing laser printer smudges and smears


Is your laser printer printing documents that are smudged or smeared? Are you ready to throw your printer out the window? Before you do, we have some recommendations for you. It may be a simpler fix than you think.

When your laser printer is producing smeared or smudged documents, it often indicates a problem with the printer’s components or consumables and will require you to open the printer and troubleshoot the problem. We are here to help you, but diagnosing the problem will require some trial and error.

Diagnosing laser printer streaks, smudges, or smears in four steps

Please read each section in the order it is presented; as they are presented in order of the most likely to least likely cause for the smudged or smeared documents you are experiencing.

Important: Always unplug your printer before reaching into it. Also, be sure to wait for your laser printer to cool down prior to touching any of its internal parts.

Failing Toner Cartridge

The most likely source of smudged or smeared print is due to a defective or worn out toner cartridge. As toner cartridges age, they can develop defects, such as the incorrect distribution of toner. This can happen with any brand, including generic, remanufactured, or genuine OEM toner.

The imaging drum transfers the print image, consisting of toner, onto the paper. If the drum itself is defective, toner may be misapplied to the paper affecting toner distribution. This incorrect distribution can result in smudges or smears on the paper.

Many smaller or inexpensive laser printers use toner cartridges that directly contain an imaging drum inside the toner cartridges. These toner cartridges are called “combined cartridges”. When needing to replace toner in a combined cartridge, the drum is automatically replaced at the same time.

Some of the larger and more professional printers such as some Lexmark and Dell, as well as many Brother printers, have separate toner cartridges and drum assemblies, which can be changed individually.

A smear or smudge that appears in addition to otherwise quality produced documents can also indicate toner contamination from a cartridge that is leaking or one that is using too much toner.

Steps to Resolve:

  • As previously mentioned, always turn your printer off and allow the printer to cool down for an adequate amount of time before attempting to change a toner cartridge.
  • Open the cover to your printer. This is typically a front-facing panel on most laser printers.
  • Grasp the handle on the cartridge and pull out the entire combined cartridge. If your printer has a separate toner and drum assembly, you may need to release the toner cartridge from the drum unit. Depending on your specific printer, this may be done with a switch, lever, or button. Do not force the cartridge out of the drum assembly.
  • Be sure to use the correct toner for your specific printer model.
  • Unpackage your new toner cartridge, line it up with the drum and press it into place. It should softly click into place.
  • While the cartridge/drum is out of your printer, you may notice a tab along its edge. Slide the tab along its edge back and forth to clean the internal corona wire. Not all cartridges/drums have this feature, but if yours does, it may help prevent print quality problems in the future.
  • Slide the combined cartridge/drum unit back into the printer. Making sure it slides all the way back into place to allow you to completely close the panel.
  • Close the front panel and turn on your printer. Wait until your display screen shows that your printer is ready to print.
Troubleshooting laser printer streaks, smudges, and smears

Paper Issues

Print smears and smudges may be due to the paper type being incompatible with your printer. Paper that is too thick, too smooth, or that has a glossy finish, may be incompatible with your printer. This can limit your laser printer’s ability to fuse toner onto your paper. If you are using anything other than standard-sized paper, you may see smudges or smears. To verify this, put standard size (8.5 x 11) and weight (20 lb.) paper in your printer. If your printer works fine with standard paper, your paper may be incompatible. If this does not resolve the problem, unfortunately, the only solution to this is to use a standard size and weight paper.

Lastly, if you live in an area with high humidity, the moisture in the air can be absorbed into the printer paper. This can cause the paper to stick together causing multiple sheets of paper to be pulled through the printer at the same time; leading to distortions. In this case, check the paper for dampness and replace it to see if this resolves the distortion.

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Toner Spill

If toner has spilled inside the printer, it may appear as multiple smudges and smears on the paper. The degree of the spill will determine whether you can fairly easily clean it up yourself or whether you should hire a competent technician. If the spill is not excessive, you can clean it up. Here are steps to help you clean it up:

Troubleshooting laser printer streaks, smudges, and smears from toner spills

Warning: Do not use a regular vacuum or compressed air. Printer toner is a very fine powder and may easily be dispersed. Additionally, there are substances in toner that are toxic and should not be inhaled.

If you were to use a regular vacuum or compressed air, it would likely create a much larger mess. There are specially designed toner vacuums with a HEPA (High-Efficiency Particulate Air) filter for cleaning up large toner spills. Most printer technicians have access to toner vacuums or you may want to purchase one.

Some supplies you will need before beginning.

Step 1: Protect yourself by putting on your rubber gloves and non-surgical face mask. This will help to prevent inhaling toner and getting it all over your skin and clothing.

Step 2: Turn your printer off and unplug the power cord from the power outlet.

Step 3: Open the cover to your printer (front-facing panel on most laser printers) and remove the toner cartridge. Be sure to place a paper towel underneath it as you pull it out and avoid tilting it unnecessarily. Place it on a dry paper towel to the side.

Step 4: If there is an excessive amount of toner, scoop it out and place it in a garbage bag and seal it. Typically, you can throw it in the trash, however, please check your local regulations to verify if this material is prohibited and dispose of it accordingly.

Step 5: If the toner spill is minor, you may use a paper towel that is slightly dampened with cool water to wipe down the surfaces at the spill site. If there is remaining toner, a toner vacuum with a HEPA filter will be necessary to remove it.

Step 6: If you have gotten any toner on your clothing, you may shake the item out over a trash can. If any toner remains, you may wash the item in cold water only. If warm or hot water is used, the toner may adhere to the garment. Remember: heat is used to fuse toner to paper and heat will also adhere toner to your clothing. Additionally, make sure that all toner is removed from clothing before using a clothes dryer or iron.

Step 7: When the toner spill has been cleaned, you may reinstall all components, reconnect all cables, and turn on the machine.

This completes the cleaning process. If you have toner on your hands, use soap and water to wash it off.

Defective Fuser

Another component in a laser printer than can cause smudging problems when not functioning properly is the fuser. The fuser is the component that delivers the heat source that bonds the toner particles to the paper. When it doesn’t heat to the proper temperature, it cannot complete the bonding process. This can lead to smudges and smears if non-fused toner sticks to the rollers.

In the event of a failing fuser, you should request service from a competent printer technician to repair it.

If none of these suggestions have helped you, please submit a request for a technician visit.

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