[dogeatdog5]

Hello, I have an extra tube that came with my machine that was never used. I recently started using it and it's only been a month. Last night it suddenly lost most of its power mid-cut. After checking focus I went home then came back in this morning. I was excited to find the laser cutting at full power again but it only lasted about 30 minutes before it lost almost all power and was barely cutting. I checked the lens for damage then checked the focus. I noticed that the laser was firing a circle with an empty middle. I then started to trouble shoot starting at the tube itself. I fired the tube onto a piece of wood and got the same thing, low power and a circle with an empty middle. I tested the power supply next and used the resister that came with the laser. The power was firing at full power so I've determined that the supply was fine. I also learned that there's a lens in the tube itself and I did a visual check looking in the end of the tube and all looked fine. I also did a visual check of the tube which looks fine. That's about as far as I've gotten but at this point I fear it's the tube that's gone or if not I don't know what else to troubleshoot. Any ideas? I've attached a photo of what the laser looks like when it hits the piece. 150W Chinese tube water chilled

[Dean448]

I had the same thing and the tube was gone. What temperature was the water? How many milliamps were you drawing?


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[dogeatdog5]

The water temp is fine. Same as it's always been. The only thing that puzzles me is that the laser light is purple and everything I read says that a purple light means the tube is good. Also, why would it work after sitting for then night for 30 more minutes? Either it has gas or it doesn't right? I didn't see any slow decline in the power, it just instantly lost power.

[dogeatdog5]

I'm only drawing 6ma since the problem arose. Using the resistor test (bypassing the tube) it's almost 40MA,. There is a slight arch at the end before it passes through the end but if what an arching problem why would it lose power? I would think the power would be the same.