Troubleshooting a failed print
Something went wrong? Don't worry — most print failures have simple solutions. 3DPrintForge helps you find the cause quickly.
Step 1 — Check the HMS error codes
HMS (Handling, Monitoring, Sensing) is Bambu Labs' error system. All errors are automatically logged in the dashboard.
- Go to Monitoring → Errors
- Find the failed print
- Click on the error code for a detailed description and suggested solution
Common HMS codes:
| Code | Description | Quick fix |
|---|---|---|
| 0700 1xxx | AMS error (jammed, motor problem) | Check filament path in AMS |
| 0300 0xxx | Extrusion error (under/over-extrusion) | Clean nozzle, check filament |
| 0500 xxxx | Calibration error | Run recalibration |
| 1200 xxxx | Temperature deviation | Check cable connections |
| 0C00 xxxx | Camera error | Restart printer |
Under History → [Print] → HMS log you can see all error codes that occurred during a print — even if the print "completed".
Common errors and solutions
Poor adhesion (first layer won't stick)
Symptoms: Print comes loose from the plate, curls up, first layer missing
Causes and solutions:
| Cause | Solution |
|---|---|
| Dirty plate | Wipe with IPA alcohol |
| Wrong plate temperature | Increase by 5°C |
| Z-offset incorrect | Run Auto Bed Leveling again |
| Missing glue stick (PETG/ABS) | Apply a thin layer of glue stick |
| First layer speed too fast | Reduce to 20–30 mm/s for first layer |
Quick checklist:
- Is the plate clean? (IPA + lint-free cloth)
- Are you using the right plate for the filament type? (see Choosing the right plate)
- Has Z-calibration been done after the last plate change?
Warping (corners lifting)
Symptoms: Corners bend up from the plate, especially on large flat models
Causes and solutions:
| Cause | Solution |
|---|---|
| Temperature difference | Close the front door on the printer |
| Missing brim | Enable brim in Bambu Studio (3–5 mm) |
| Plate too cold | Increase plate temperature by 5–10°C |
| High-shrinkage filament (ABS) | Use Engineering Plate + chamber >40°C |
ABS and ASA are especially prone to this. Always ensure:
- Front door closed
- Minimal ventilation
- Engineering Plate + glue stick
- Chamber temperature 40°C+
Stringing (threads between parts)
Symptoms: Fine plastic threads between separate parts of the model
Causes and solutions:
| Cause | Solution |
|---|---|
| Wet filament | Dry filament 6–8 hours (60–70°C) |
| Nozzle temperature too high | Lower by 5°C |
| Too little retraction | Increase retraction length in Bambu Studio |
| Travel speed too low | Increase travel speed to 200+ mm/s |
The moisture test: Listen for popping sounds or look for bubbles in the extrusion — that indicates wet filament. Bambu AMS has built-in humidity measurement; check humidity under AMS status.
Invest in a filament dryer (e.g. Bambu Filament Dryer) if you work with nylon or TPU — these absorb moisture in under 12 hours.
Spaghetti (print collapses into a mess)
Symptoms: Filament hanging in loose strands in the air, print is unrecognizable
Causes and solutions:
| Cause | Solution |
|---|---|
| Poor adhesion early → came loose → collapsed | See the adhesion section above |
| Speed too high | Reduce speed by 20–30% |
| Wrong support configuration | Enable supports in Bambu Studio |
| Overhang too steep | Split the model or rotate 45° |
Use Print Guard to stop spaghetti automatically — see the next section.
Under-extrusion (thin, weak layers)
Symptoms: Layers are not solid, holes in walls, weak model
Causes and solutions:
| Cause | Solution |
|---|---|
| Partially clogged nozzle | Run Cold Pull (see maintenance) |
| Filament too wet | Dry filament |
| Temperature too low | Increase nozzle temperature by 5–10°C |
| Speed too high | Reduce by 20–30% |
| PTFE tube damaged | Inspect and replace PTFE tube |
Using Print Guard for automatic protection
Print Guard monitors camera images using image recognition and automatically stops the print if spaghetti is detected.
Enabling Print Guard:
- Go to Monitoring → Print Guard
- Enable Automatic detection
- Select action: Pause (recommended) or Cancel
- Set sensitivity (start with Medium)
When Print Guard intervenes:
- You receive a notification with a camera image of what was detected
- The print is paused
- You can choose: Continue (if false positive) or Cancel print
Print Guard can occasionally react to models with many thin columns. Lower the sensitivity or temporarily disable it for complex models.
Diagnostic tools in the dashboard
Temperature log
Under History → [Print] → Temperatures you can see the temperature curve throughout the entire print. Look for:
- Sudden temperature drops (nozzle or plate problem)
- Uneven temperatures (calibration needed)
Filament statistics
Check whether the filament consumed matches the estimate. Large discrepancies can indicate under-extrusion or filament breakage.
When to contact support?
Contact Bambu Labs support if:
- The HMS code repeats itself after you have followed all the suggested solutions
- You see mechanical damage to the printer (bent rods, broken gears)
- Temperature values are impossible (e.g. nozzle reads -40°C)
- A firmware update does not solve the problem
Useful information to have ready for support:
- HMS error codes from the dashboard's error log
- Camera image of the failure
- Which filament and settings were used (can be exported from history)
- Printer model and firmware version (shown under Settings → Printer → Info)