@jason Are the wires you’re using for laser power thick enough to handle the 3 current, or at least 2 amps? Was the laser driver “tuned” before connecting it to the Ramps board and applying power? And finally, double-check the polarity on the driver’s power inputs. I noticed that on some of the newer driver variants out there, the JST connector goes into the power connection with the positive lead connected to the negative output on the board and vise-versa. If this is what happened with yours then you most likely toasted your Ramps and possibly your mega board too. See the link below for details.