My K40 seems to be losing power. It's struggling to cut 2mm acrylic cleanly at 15mA, 10mm/s speed.

In the past I am sure it would cut at 10mA, 20mm/s.

Its a few years old, but doesn't get used very much at all.

I've cleaned the mirrors and the lens in the tube and the head.

I've noticed that cuts seem to vary in depth so parts don't release cleanly when some of the cut is not all the way through.

Anything else I can check, or is this just age related degradation?

Would a set of new mirrors help?

Am I expecting too much from it?

Cheers!