u3fi-6670

Fujitsu fi-6670 error U3: Sensor Troubleshooting

The Fujitsu fi-6670 error U3 indicates a problem with the Automatic Document Feeder (ADF) sensor. This error occurs when the scanner can no longer correctly detect the paper path or input documents, causing a halt to prevent damage. This is often caused by dust or adhesive buildup on the sensor lens.

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Common causes

  • 1Dust on the sensor optical path.
  • 2Adhesive residue from labels.
  • 3Debris blocking the feed path.
  • 4Faulty optical detection sensor.

Solutions

Quick Diagnosis

If you see error U3, the scanner likely believes it is jammed or that there is a physical obstacle in the ADF input. Check carefully for paper bits or sticky label remnants.

Step-by-Step Fix

  1. Access: Open the main ADF cover to reveal the document sensors.
  2. Clean: Use a dry, lint-free cloth to gently wipe the glass surfaces covering the sensors.
  3. Check: Ensure the sensor lever is not sticky and springs back into place after movement.
  4. Power Cycle: Turn the scanner off and on again to clear the logic error.

Prevention and Maintenance

Regular use of Fujitsu's cleaning kits is the best defense against sensor errors. Do not run documents that have been taped or stapled through the scanner.

When to Call a Technician

If the U3 error remains after cleaning the optical components, the sensor hardware might need professional calibration or component replacement.

Equipment Technical Data

  • Technology: High-volume ADF Scanner
  • Consumables: Genuine roller replacement kits
  • Hardware: Multiple optical document sensors
  • Maintenance: Routine sensor cleaning
  • Usage: Corporate scanning workflows
  • Official Drivers / Firmware

Steps to follow

  1. 1

    Clean sensors

    Wipe the paper input sensors with a clean, dry cloth.

  2. 2

    Inspect ADF

    Check for obstructions like staples or paper clips.

  3. 3

    Power reset

    Cycle the power to reset the sensor system.

Frequently asked questions

The U3 error indicates a sensor communication issue, typically caused by debris blocking the optical path.

Yes, regular maintenance and ensuring document quality will keep the sensors clean.

Use official roller kits to maintain optimal scanner performance.

It is a performance-limiting fault but usually easily resolved with proper cleaning.