If your Monport K40’s output has dropped off over time, aligning the mirrors is routine maintenance that can help get it back where it should be.
I start by prepping the laser and putting masking tape down to mark reference points. Then I adjust each mirror one at a time, and small adjustments make a bigger difference than you’d think.
Not every mirror is adjusted the same way. Some involve moving the tube itself, while others mean adjusting the mirror directly. After making changes, check all four corners.
Keep up with this regularly and your laser will cut and engrave better for it.