Kyocera error code
C4000Polygon motor synchronisation error
🔧 Needs an engineer
What it means
The polygon mirror motor in the laser scanner unit did not reach a stable speed, so the machine cannot write the image.
Common causes
- Worn polygon motor bearing (often heard as a whine)
- Faulty laser scanner unit
- Loose cable between laser unit and main board
What you can safely try
- 1Switch the machine off, wait 30 seconds and switch it on again — note whether the code comes back.
- 2Let the machine rest for 15–20 minutes if the room is very hot or humid, then switch it on again.
- 3The laser unit is sealed — do not open it. If the code returns, the unit or its board needs an engineer.
- 4Take a photo of the display and note the machine model and its meter reading before you call.
⚠️ If the code comes back after a restart, stop using the machine and call an engineer — running it on can damage more parts.
The exact meaning can vary slightly between models. Send us the model number for a precise diagnosis.