Fiber Troubleshooting

Common symptoms and the first thing to check.

Mark is weak / barely visible

• Focus. Re-check Z. (90% of cases.)
• Lens is dirty.
• Power scaled down accidentally in Lightburn (check layer settings).
• Wrong lens loaded vs. correction file.

Mark is too aggressive / burning through

• Defocus too low, raise Z.
• Speed too low.
• Frequency too high (driving too much energy into the same spot).

Color annealing won't repeat

• Surface contamination, clean with IPA.
• Different alloy lot, even "304 stainless" varies; re-test.
• Z drift. Verify focus.

Distortion (square comes out trapezoid)

• Wrong correction file loaded.
• Lens calibration drifted; re-run lens calibration wizard.

Red dot doesn't match where it marks

• Run the alignment wizard.
• Verify Z is at correct focus distance.

Galvo not connecting in Lightburn

• USB cable swap (cheap cables fail).
• Driver: ensure JCZ/BJJCZ driver installed.
• Power cycle the laser before starting Lightburn.

Rotary spinning wrong direction or wrong distance

• Steps-per-rotation wrong; check motor spec.
• Object diameter not what you measured; re-caliper.
• Reverse axis direction toggle in rotary settings.