Can not get the laser to fire using the MDI M3S… Settings. Fan is running but the only way the laser will fire is to press the reset button. Have looked at all the videos I can find but can not find the possible problem!
I just upgraded from the original 7w to the 24w laser, and on both units you have to have the switch on, key lock on, and press the little reset button inside. I think it’s an extra layer of safety. Both my laser units came with a glossy page that shows the connections and shows the rest button.

Hope this helps.
Paul
I changed the selector switch so that the laser would not fire full power. So now when I restart it I have to press the reset button and one green light comes on. I tried several ways to enter the MDI codes and when I press enter they disappear and the laser does not fire. Everything is hooked up properly.
Did you ever find a solution? mine is doing something similar and i cannot find a reason why??
I had the same problem. I spent about 2 hrs trying to figure it out when I discovered that I had the black switch (located below the 2 green indicator lights) in the down position instead of the up position on the laser controller.
Are you putting a space between the M3 and the S? This works for me.
Try this in the mdi tab
M3 S1000