Why Is My Multifunction Printer Printing Lines? (And How to Fix It)
There is few things more frustrating than rushing to print an important document, only to pull it from the tray and find it covered in annoying streaks, faded lines, or random smudges. If your trusty multifunction printer (MFP) has suddenly decided to become a modern art machine, don't panic.
Printer lines are one of the most common issues offices and home users face. Because multifunction printers handle printing, scanning, and copying, the causes can vary.
In this blog post, we’ll break down why your printer is producing lines and provide step-by-step troubleshooting tips to get your documents looking pristine again.
The Culprits: Why Are Lines Appearing?
Before you reach for the wrench, it helps to understand what kind of lines you are looking at. Are they vertical or horizontal? Are they colored or white?
Here is a quick diagnostic guide to help you identify the source of the problem:
| Type of Line | Common Cause (Inkjet) | Common Cause (Laser) |
|---|---|---|
| Vertical White Streaks | Clogged printhead nozzles | Low toner, scratched drum, or dirty scanner glass |
| Horizontal Faded Lines | Low ink levels or misaligned printhead | Faulty transfer roller or gear issue |
| Random Colored Lines | Damaged printhead or severe ink leak | Toner cartridge leak or damaged fuser |
| Smudged/Wavy Lines | Excess ink on rollers | Toner not fusing properly (faulty fuser) |
On smaller screens, swipe horizontally to view the complete diagnostic table.
Step-by-Step Troubleshooting Guide
Follow these steps from easiest to most advanced to fix those annoying lines.
1. Run a Printhead Cleaning (Inkjet Printers)
If you use an inkjet printer and notice blank vertical lines, your printhead nozzles are likely dried out or clogged.
The Fix: Go to your computer's printer settings (or the printer’s control panel) and look for Maintenance or Utilities. Select Clean Printhead or Deep Clean. Print a test page afterward to check the results. You may need to run this 2–3 times.
2. Clean the Scanner Glass and ADF (All Printers)
Plot twist: Your printer might not actually be printing the lines—it might be copying or scanning them onto the page! If the lines only appear when you make a photocopy or use the Automatic Document Feeder (ADF), this is definitely the issue.
The Fix: Take a soft, lint-free cloth and some isopropyl alcohol (or glass cleaner sprayed onto the cloth, never directly onto the glass). Wipe down the main scanner glass, and pay special attention to the small glass strip on the side used by the ADF, where a speck of dust or correction fluid can trick the scanner into drawing a permanent black line.
3. Check and Replace Your Toner/Ink Cartridges
Low supplies or a leaking cartridge will frequently result in streaks.
The Fix: Remove your ink or toner cartridges. Give toner cartridges a gentle rock horizontally to redistribute the powder (be careful not to touch the drum). Check for any physical leaks. If a cartridge is nearly empty, replace it.
4. Inspect the Drum Unit (Laser Printers)
Laser printers use a photosensitive drum to transfer toner to the paper. If the drum gets scratched, has toner baked onto it, or wears out, it will leave a vertical line down every page.
The Fix: Remove the drum unit (sometimes built into the toner cartridge). Look closely at the shiny cylinder. If you see a streak of dried toner, gently wipe it off with a dry, lint-free cotton swab. Do not use harsh chemicals or touch the shiny surface with your bare fingers. If the drum is physically scratched, you will need to replace the drum unit.
5. Align the Printhead
Sometimes, the printer mechanics get slightly out of alignment, causing overlapping passes or white gaps.
The Fix: Navigate to your printer's maintenance menu on your computer or touchscreen and select Align Printhead. Follow the on-screen instructions.
Frequently Asked Questions (FAQ)
Wrapping Up
Dealing with lines on your printed documents can be a headache, but in most cases, the fix is as simple as running a maintenance cycle or wiping down the scanner glass. Start with the easiest fixes—like cleaning and alignment—before spending money on replacement parts.
Did these tips help clear up your prints? Let us know in the comments below!
Keep Your MFP Printing Clearly
Regular cleaning, proper toner and ink management, scanner glass care, drum inspection, and preventive MFP maintenance can help reduce streaks, lines, smudges, and other common print-quality problems in busy offices.