[monkeyfist]

I noticed the burn mark had changed, before the lens. And upon closer inspection that the laser seems to burn the mirror that is inside the laser tube. At the back of it.

Is this common? It should be properly cooled, as it's the first place where the water hits. And the water in the bucket has never been over room temperature.

I assume there is no way to change the mirror, as it's inside a sealed glass tube with the gasses.

You can see it burning from this photo, or is this normal?

[monkeyfist]

No replies? So i assume this is not common or something it should be doing?

[gfacer]

No idea what is going on but it shouldn't look like that. Crap in the tube that finally went to the wrong spot? We just had a failure similar here....on the output lens side and looking at some other broken tubes I noticed one that had a lot of crap on the back side the the lens.

They cannot be fixed.

[monkeyfist]

No idea what is going on but it shouldn't look like that. Crap in the tube that finally went to the wrong spot? We just had a failure similar here....on the output lens side and looking at some other broken tubes I noticed one that had a lot of crap on the back side the the lens.

They cannot be fixed.

Ok, this is what i thought. There had to be something that started to burn on the mirror... when i look at it now, there is definitely a burn mark or a hole in the mirror.

Luckily the seller will refund the price of a new tube, so have to think about upgrading to 50w 100mm tube as it might be a smart thing to do now..