How to solve the problem if a laser marking machine can not mark clearly?

What to do if the laser marking machine has weak beam and unclear marking?

3 steps to find out the problem:  

First, check if the focal length is correct or not.  Let the 2 red dots overlap. 

Second, check if there is dust on the filed lens. 

Third, check if the parameters are correct.   

Other problems might the cable line is loose, bad signal, or the laser is aging.