Chinese CO2 laser not working, causes and solutions?

Question

lasers

Hello. I got a Chinese engraver in my hands. I received it not from China, but from mentors, they say that it is necessary to fix it or find the cause. Having understood them a little, I decided to write here.
So I could not find out the laser model, but I

worked for about an hour and stopped. The thermal paper placed after the tube does not change color, although the discharge is on, there is a video of the discharge. There is no water sensor on it, it is closed at the factory in the place of the sensor. Interested in what could be the reasons, and how exactly to make sure of them?
Personally, I think on the tube (depressurization. I would be glad for any help.

Answer 1

They have a test button on the power supplies. Need to try. If they shoot with it, then the matter is in the control signal. If not, then you can narrow down the search for problems in the BP-tube area.