Troubleshooting
Diagnose and fix common issues. Sorted by frequency in real customer cases.
Start from the message
Section titled “Start from the message”If the printer is showing you an error, go straight to Error messages — every Klipper string the machine produces, and the page that explains it.
Top issues
Section titled “Top issues”Feeding system
Section titled “Feeding system”- Hopper suction problems — pellets don’t reach the hopper, vacuum struggles, shutdown during suction (most frequent overall)
First-layer & calibration
Section titled “First-layer & calibration”- Z offset and first layer — first layer too high / too low / not sticking
Extrusion
Section titled “Extrusion”- Nozzle and barrel clog — material plugged in the extruder
- Extruder motor skipping — clicking sound, motor losing steps
- Extruder driver and 55V step-up — motor stops/skips due to an electrical fault (driver / 55V boost)
- Print quality — which page — start from what the print looks like
- Layer shift — offset layers; most are the nozzle clipping the layer below
- Blobs and stringing — corners, line starts, travel moves, solid infill
- Surface finish — turbulent walls, stripes, wavy first layer, clear material
- Black splashes and nozzle degradation — carbonized material in nozzle after long runs
Material problems
Section titled “Material problems”- PETG foaming and moisture — wet PETG, bubbles, foaming
- Warping — corners lifting; material choice, bed temp, brim
- Color streaks and pigment dosing — uneven color, transparent streaks, masterbatch %
Electrical & first boot
Section titled “Electrical & first boot”- Bed heater on wrong outlet — bed heats by itself / 110°C error
- Machine won’t start - emergency button — red mushroom pressed
- Klipper MCU communication lost — MCU shutdown errors
- Running the G1 in 110V regions (US) — split-phase 240V vs step-up converters
Temperature
Section titled “Temperature”- Temperature sensor disconnected — NTC unplugged or pulled out
- Display stuck after a Moonraker update — screen shows Unauthorized, browser works fine
- Heater not reaching temperature — heater drops during print, fan blowing on the sensor, relay and supply faults
Mechanics
Section titled “Mechanics”- Belt and pulley mechanical issues — loose belts, frame issues
- Probe arm bending — probe stuck, not triggering, physically bent arm
Bed adhesion
Section titled “Bed adhesion”- Bed adhesion sprays — DimaFix, MagiGoo, RainX, etc.
- Bed surface — glass cracking (PETG bonds too hard), surface options per material
Safety
Section titled “Safety”- Safety and fumes — ventilation, recognizing contaminated material, ABS/ASA hazards
Slicer
Section titled “Slicer”- FGF-specific settings — why the print slows down, retraction, Z-hop, Arachne, Pressure Advance
Diagnostic tree
Section titled “Diagnostic tree”Not sure where to start? Pick the closest symptom:
| Symptom | Likely note |
|---|---|
| Machine doesn’t turn on | Machine won’t start - emergency button |
| Bed heats by itself, error at 110°C | Bed heater on wrong outlet |
| Klipper says “MCU shutdown” | Klipper MCU communication lost |
| Printer’s display says Unauthorized, browser is fine | Display stuck after a Moonraker update |
| Temperature error on a heating zone | Temperature sensor disconnected or Heater not reaching temperature |
| Pellets don’t reach the hopper | Hopper suction problems |
| Loud “tak-tak-tak” from the motor | Extruder motor skipping |
| PETG looks foamy, full of bubbles | PETG foaming and moisture |
| First layer too high / too low | Z offset and first layer |
| Nozzle / extruder clogged | Nozzle and barrel clog |
Status legend
Section titled “Status legend”- v1 (green) — reviewed and confirmed by Davide
- v0 (yellow) — extracted from chats / docs, not yet human-reviewed
Future human review passes bump the version (v2, v3, …).
Related
Section titled “Related”- Components — hardware reference
- Materials — material-specific issues
- Procedures — corrective procedures