So I've been using an Epilog Radius 25w laser engraver for the last 5 years or so. And about a year or so ago, I've noticed that the power has steadily been declining. Jobs that I used to run at SPEED-100, POWER-70 now have to be ran at SPEED-60, POWER-80 with multiple passes to look decent. My first reaction was to replace the lens as it was nasty. I've done that and I have seen next to no increase in performance.
How do I go about trying to identify and solve the problem in my loss of performance?