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 |
:::tip Error codes in history 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.
:::tip Filament dryer 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
:::info False positives 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)