Error 520 on OKI MC363dn: Scanner Issues Fix
The error 520 on the OKI MC363dn multifunction printer indicates that the scanning unit cannot perform its normal path due to an obstruction or failure in the carriage motor. This error usually appears when starting the machine as it attempts the automatic image sensor calibration process. If the scanner does not move freely, the machine will lock automatically as a protective measure.
Common causes
- 1Physical obstruction by foreign objects on the scanner glass.
- 2Excessive dirt on the scanner guide rails.
- 3Electrical failure in the scanner stepper motor.
Solutions
Unlocking the Carriage
- Turn off the unit and unplug the device.
- Lift the top cover and check if any objects are blocking the internal glass.
- If the carriage is stuck, do not apply excessive force; try moving it gently by hand toward the center.
Scanner Internal Cleaning
- Use a soft microfiber cloth.
- Carefully clean the scanner's sliding guides.
- Ensure no label residues or staples are in the path of movement.
Steps to follow
- 1
Check for Blockages
Lift the scanner unit and observe if the glass has debris or if the carriage is caught.
- 2
Guide Cleaning
Wipe the metal bars where the scanner moves with a dry cloth.
- 3
Initialization Test
Close everything, reconnect power, and turn on the printer to let it run its calibration cycle.
Frequently asked questions
Yes, only when the machine is turned off and always gently, without applying excessive pressure.
If the error persists, the scanner motor may have permanent damage and require technical replacement.
Error 520 locks all functions of the multifunction device, including printing, to protect system integrity.