I followed all the posts on this forum, spend a considerable amount of time with customer support (witch b.t.w. is the best I have even seen…) ultimately they send me a new controller.
fired up the laser did a few files. shut it all down to do some carving.
switched out to laser again and…
doesn’t work again…sigh !!!
my question here is: can someone tell met step-by-step how to start lasering including the setup in the software
What software are you using? In VCarve you create a gcode file and send it to the controller just like the ngc file. Remove any bits in the router and connect the laser. Be sure to check in the drop down menu under tools that dynamic power is checked. Turn on the laser and check that the fan is running. Hit start and run the gcode.
All is good, by accident I found the problem that the connector wasn’t soldered properly on the circuit board.
Thanks to the support department (best ever) I now receive a…" BRAND NEW LASER". 
Cor, did you use Jtech or Onefinity support?
i have used both the helpdesks