First, you need to make sure that your laser tube is filled with water and there are no bubbles in it.
Align the tube to the center of the mirror by adjusting the mounting of the tube. Then, put a piece of tape or post-it on mirror.
After that, set the max power to about 12% and press pulse. Make sure that the spot is in the right center.
For mirror 2, do the same thing once and if the spot is in the center, move it and pulse again to see if two points coincide.
Adjust mirror 1 when pulse mirror 2. For mirror 3, adjust mirror 2 to make the two pulse spots are the same.
Finally, test the laser head by setting a tape on it. A double dot or a half-moon means the laser beam is hitting the metal.
The laser head should be checked at all 4 corners of the machine.
And it’s normal for the laser beam at mirror 1 to be two-spotted or two half-moon like. What needs to be checked is the end result.