12601
Easy Fix
Prusa · FDM 3D Printers
Filament Sensor - No Filament Detected
Quick Answer
Error code 12601 on your Prusa FDM 3D Printers means: Filament Sensor - No Filament Detected. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
How to Fix It
1
Check if the filament spool still has material remaining
2
Inspect the filament path from spool holder through PTFE tube to the filament sensor for breaks
3
Remove filament from the sensor and blow compressed air through the sensor housing
4
Verify the filament sensor cable is connected on the mainboard
5
Test sensor functionality: LCD > Support > Sensor Info and manually feed filament to check for detection
Pro Tip
This is a common issue that most users can resolve without specialized tools. Try the first step before moving on to more complex solutions.
Parts You May Need
Replacement filament sensor (IR sensor for MK3S+, optical encoder for MK4)
PTFE tube (3mm ID/4mm OD)
Related Error Codes