Machine failure

Hi folks...

I've had a K40 (Chinesium laser cutter) for about a year now with very intermittent use and today it stopped lasering.

I don't know what's wrong exactly but I will describe whats going on and maybe someone can point me in the right direction.

It was working quite well until this AM when I was trying to figure out the power/speed settings and trying different firmware on my controller.

The beam seemed to be getting weaker and weaker the longer I was using it, and now I get no output at all...

I am no longer using the software, only the hardware laser test button and I've tried the power pot in all positions.

I put a piece of paper on the end of the tube and it did not effect it at all, no marks, no fire, nothing.

There is a thin line of light along the tube when I fire the laser (I was using my camera, I am not sure if I can safely look at the tube while it's on)

If I turn the pot between 0 and 10 mA I hear a hissing/buzzing noise from the PSU but as soon as I get to or above 10 the noise goes away completely.

I'm also occasionally hearing a loud bang/popping noise but it happens pretty randomly.

Does this sound like the power supply has died, or does it sound like it's the tube?

Or could it be something else like a bad wire or dirty water or something else?

The tube doesn't look broken but I'm not sure what I'd be looking for...

Any advice is appreciated.

I fired the laser with the case off and it was arcing and sparking and it caught on fire.. Had to extinguish it.... Clearing out the smoke right now... Still not sure what's wrong but clearly the power supply is putting out enough voltage to cause a fire...