Cohesion 3d upgrade on a k40/noise

I have a k40 laser, the board was an m2nano. I upgraded the board to cohesion 3d with smoothie ware. When I plug in the cohesion board there is a noise coming from my machine that wasn’t there before. The noise sounds like a whistle/buzzing.

It’s fine. It’s just the steppers being held in place. My CNC machines do the same thing. Nothing to worry about.

The FAQ entry and further discussion on this topic is here, please have a read:

Ok. Thank you for the help.