Its hard to see the arc. Is it inside the tube or arching to the case anywhere?
Looks more like inside the tube?
This could be either a tube or a power supply, its hard to know which.
Can you see any arching inside the power supply.
– I do not see the tube ionizing.
– Since this was a sudden failure my bet would be the LPS. Further I would suspect the HV transformer.
You can try testing it this way:
WARNING: the LPS outputs lethal voltage. At all times stay away from the laser tube while power is applied
YOU DO THE FOLLOWING TEST AT YOUR OWN RISK
With power off:
You can connect one end of a wire to ground and tape the other end to the tube about 1" away from the anode.
With power on and your positioned away from the tube:
Turn on the machines power and briefly push the test button to fire the laser. Caution: Do not hold down on the button. Arching to ground for long periods can damage the LPS.
If you get a violent arch from the anode to the ground wire then your problem is likely your tube.
If you don’t get a strong arc or any arc at all your LPS is bad.
You can buy a new LPS or replace the HVT in your current unit.