General Print Quality Troubleshooting Guide

Overview

If your OKI printer is producing prints that do not look right, this guide helps you identify the problem and find the correct solution. Use the table below to match what you see on the print to the right article.

This guide covers all OKI printers supplied by Mediaset: C650, C844, MC853, MC873, MC883, ES8453, ES8473, ES8483, and Pro9431.

What Do You See on the Print?

Use this decision guide to find the right article for your problem.

Dots or Spots

What it looks like: Small black or white dots, spots, or specks that repeat at regular intervals down the page.

Most likely cause: Damaged or dirty image drum, fuser unit, or transfer belt. The spacing between the dots tells you which component is responsible.

What to do: → Black or White Dots on Prints

Periodic Lines or Horizontal Streaks

What it looks like: Thin lines or bands running across the page (perpendicular to the print direction), repeating at regular intervals.

Most likely cause: Foreign objects on the drum or belt, or a worn fuser roller.

What to do: → Periodic Dots and Horizontal Streaks

Marks on the Back of the Page

What it looks like: Black smudges, toner marks, or streaks on the reverse side of the printed sheet.

Most likely cause: Toner buildup on the fuser unit or on the paper path rollers.

What to do: → Black Marks on Back of Page

As an immediate step, try running a Drum Cleaning Page: → How to Generate a Drum Cleaning Page

Faded or Light Prints

What it looks like: Text or images appear washed out, faint, or lighter than expected. Colours may appear dull.

Most likely cause: Low toner, dirty LED head, worn image drum, or incorrect media type settings.

What to do: → Faded or Light Prints Quick checks:

Check the toner level on the printer's status page or operator panel.
Clean the LED heads with a soft, dry cloth.
Verify the paper type setting matches the media you are using (e.g., "Plain" vs. "Heavy").

Colour Misalignment or Banding

What it looks like: Colours do not line up correctly — text has coloured shadows, or thin white gaps appear between colour areas. Colour bands may shift horizontally.

Most likely cause: The colour registration is out of alignment. This can happen after moving the printer, after a paper jam, or simply over time.

What to do: → Color Misalignment / Banding Quick fix: Run auto colour registration from the printer menu:

C650 / C844: Menu > Maintenance > Color Registration > Auto Adjust
MC853 / MC873 / MC883 / ES8453: Device Settings > Maintenance > Color Registration > Auto

Vertical White Lines

What it looks like: One or more thin white lines running the full length of the page in the print direction.

Most likely cause: Dirty LED head. Dust or toner particles on the LED head block the light, leaving white lines on the print.

What to do:

Open the front cover.
Locate the LED heads (narrow glass strips above each drum slot).
Wipe each LED head gently with a soft, dry, lint-free cloth.
Close the cover and print a test page.

If the white lines persist after cleaning, the LED head or image drum may need replacing.

Paper Jams Causing Print Defects

What it looks like: After clearing a paper jam, subsequent prints show smudges, streaks, or repeating marks that were not there before.

Most likely cause: The paper jam may have scratched the transfer belt or left toner residue on the fuser rollers.

What to do:

Run a Drum Cleaning Page to clear residual toner: → How to Generate a Drum Cleaning Page
Print 5–10 blank pages to allow the fuser to self-clean.
If marks persist, check the transfer belt for scratches: → Black or White Dots on Prints

General Maintenance Steps

Before diving into specific troubleshooting, try these steps — they resolve most common print quality issues:

Run a Drum Cleaning Page. This clears toner residue from the drum. → How to Generate a Drum Cleaning Page

Clean the LED heads. Open the front cover and wipe each LED head with a soft, dry cloth.

Check toner levels. Low toner can cause faded prints, streaks, or uneven colour.

Run auto colour registration. Fixes colour alignment issues after jams, transport, or consumable replacement.

Check the paper. Damp, wrinkled, or poor-quality paper causes many print issues. Store paper in a dry location and use the correct media type setting.

When to Contact Mediaset Support

The problem persists after following the steps in the relevant article.
You see an error code on the printer display. → Check our Error Codes section.
A consumable needs replacing, and you are unsure which part to order.
You have recently replaced a consumable, and the print quality has not improved.

When contacting support, include:

Your printer model (e.g., OKI C650, MC883)
A photo or scan of the affected print
Any error codes shown on the display
Which troubleshooting steps have you already tried

Mediaset Support: support@mediaset.no

Print Quality Issues

Maintenance & Cleaning

Category: Print Quality Issues Tags: print quality, troubleshooting, OKI, dots, streaks, faded, banding, colour, misalignment, white lines Applies to: OKI C650, C844, MC853, MC873, MC883, ES8453, ES8473, ES8483, Pro9431

Last updated: March 2026