1. First, is the focal length adjusted properly?
2. Is there too much-soaked paper covering the engraved material or too much water on the paper?
3. Is the laser tube aging?
4. Is the optical path correct? (Recalibrate)
5. The lens is dirty and the dust is too thick.
6. The lens is broken
7. The laser tube head is dirty.
8. Is the power selected too low? Then it would be best if you replaced the laser machine with a higher power.