Laser drawing a dotted line

[Woodgenie]

This is a 45W unit. Laser is cutting an intermittent dotted line which becomes very obvious at lower power.
The HV wiring looks fine, has anyone run into this problem? The picture shows the result at different power levels.
Thank you.

[Woodgenie]

I have also had this problem with my 45W laser. Have replaced the HV PSU, lens alignment is good.

Laser cut quality.jpg (78.71 KiB) Viewed 154 times

I also notice the line gets weaker on straight lines, i assume because the speed is higher.

Minion cuts.jpg (65.11 KiB) Viewed 154 times

Is this sign of a dying tube possibly?

[Tech_Marco]

Seems that the laser tube is running out of gas 'CO2'. Time for a new tube

[Woodgenie]

The problem was that speed was too fast, gantry slows down on corners so burning fine there. Lowered the speed and cut quality is fine. Regarding no fire and dotted fire at low power, LO responded that this is typical of many CO2 tubes.