I guys I try to engrave and nothings happens
I need help 
You need to check the mirror alignment.
Hey. Looks to me like your mirror alignment may be out and maybe the X and Y axis rails going by most experiences with the K40. Check the mirrors first using masking tape on the first fixed mirror, then work your way to the head. Read up all you can on mirror alignment as itβs a PITA the first time you have to do it. It looks like your piece of paper has been zapped a couple of times, so that could point to bed alignment as well if you get some laser engaging working in certain parts of the travel range only. The laser is firing, so it can only be alignment at this stage
I made the alignment last night and the beam hits in the middle of the mirrors 
Then the beam is most likely hitting the inside of the head. Check and make sure the lens is seated properly. I had this happen to me once.
Iβm going to check that thanks 
hi guys just to tells that one mirror and the lens was dirty, i just clean and now its working fine thankss for your time 