Lines showing up on printed pages

Symptoms

• Thin horizontal or vertical lines running through printed pages
• Lines repeat at a consistent interval down the page
• Line appears in the same spot on every page
• One color shows lines while others print clean

Likely causes

• CommonClogged inkjet nozzleA blocked nozzle produces a consistent thin line or gap in that color across the page.
• CommonScratched or damaged toner drum (laser printers)A scratch or debris on the drum leaves a repeating mark at a fixed interval matching the drum's circumference.
• PossibleDebris or residue on the print head or drumDust, paper fibers, or dried ink/toner can create a line until cleaned off.
• PossibleDamaged transfer roller or fuser (laser printers)Wear in these components can also create repeating marks or smudges.

What to do

1. Run a nozzle check pattern (inkjet) to identify which color has a clog and run the cleaning cycle.
2. Measure the distance between repeating lines on a laser-printed page; a consistent repeat distance often matches the circumference of the drum, pointing to a drum scratch.
3. Open the printer and visually inspect the drum unit (usually inside the toner cartridge assembly) for visible scratches, scuffs, or debris under good lighting.
4. Gently clean the print head contacts and surrounding area with a dry, lint-free cloth if accessible without disassembly.
5. For laser printers, try replacing just the drum unit if it's separate from the toner cartridge and shows visible damage.
6. Run several test pages after each fix attempt to confirm whether the line pattern has changed or disappeared.

Tools and parts

• Lint-free cloth
• Ruler (to measure repeat interval)

When to call a pro

If a repeating line matches a scratched drum and replacing the drum unit doesn't resolve it, or the cause isn't clear from inspection, a printer repair technician can pinpoint the exact worn component.

Safety