What happened?

The printer is showing the message "Hotend fan not spinning. Check it for possible debris, then inspect the wiring."

Error name: Hotend fan error

Error code: #31828 (CORE One) #35828 (CORE One L) #26828 (MK4S) #27828 (MK3.9S) #13828 (MK4) #21828 (MK3.9) #17828 (XL)

How to fix it?

Check if nothing is stopping the fan from spinning. Use compressed air to clean the fan blades.

Make sure that the fan is installed correctly.

Prusa CORE One, CORE One L	Original Prusa XL
Original Prusa MK4/S, MK3.9/S	Original Prusa MINI/+

If the issue persists, check the fan cables:

Loveboard wiring (CORE One, CORE One L, MK4/S, MK3.9/S)	Dwarf board (XL)

Buddy board (MINI/+)

In case you see any damage, make some 写真・動画の撮影 and contact our カスタマーサポート.