Up at the top, you mention you’ve been using the machine for about five years.
Unfortunately, that means it’s about time for some hardware failures:
- Laser tube life is utterly unpredictable
- High-voltage power supply to the laser tube
- Low-voltage power supply (controller, motors, etc)
A glitchy low-voltage supply (typically 24 VDC) can cause mysterious controller problems. The sellers sometimes / often / always install a power supply with a lower current rating than the total drawn by all the hardware. This works, because most supplies can produce more current than their rating, but it tends to cause early failures.
Those supplies are relatively cheap and easily replaced, so when the controller gets glitchy, replacing the supply is the first step.
This can be caused by an old tube or a failing high voltage supply. Given the age of the machine, it could be either or both.
Before jumping to conclusions, verify that the tube is resonating in the proper mode. This lengthy discussion goes over the details:
If the tube isn’t resonating in TEM00 mode, then it’s time for a new tube. If it does seem OK, then I’d suspect the power supply.