Fiber laser loses power after about 2 seconds

I have 2 triumph 50w lasers. One I bought 3 years ago and have put about 5000hrs on.

I’m having an issue with both that has me scratching my head. The laser power seems to fluctuate. The most obvious of this is the laser will fire full 100% but then about 2-3s into the program it slowly fades out to 50% or less power. If I start the program again it will do the same again.

This same issue happened with the old machine

I come from a background in gantry lasers and you can clean, align, and tweak all sorts of things when the power gets weird, but in galvos all I can really do it check the mirrors and lens. I’ve done that with no improvement.

I suppose the issue could be the power supply or tube, however this has happened on both machines under 5000hrs (and past warranty ). Is this just the standard experience for these Chinese galvos? Is there any way to fix this or is it really just to trash the entire power/tube and replace?

Is it a CO2 galvo? If yes, and a glass tube, you would certainly be up against the tube’s lifespan.

If a fiber source, or otherwise, you can get just the source repaired or replaced. The galvos in the scanhead are probably fine.

It’s fiber, which is why I wonder if something else is going on. Both fiber sources dying before 5000hrs?

You should get a lot more hours out of it than that… Most have 100k hours as the MTBF. This is my MOPA…


This is one of the smaller ones… it’s not a MOPA. I didn’t dig into this devices source type.


There is no tube in these… They are completely solid state.

If both are doing this, I would doubt you have a hardware issue.

Is this a Raycus source?


I believe the source is a raycus 50w. I’d say the most glaring issue is when it dies out as it goes across the program. For example, it seems full power as it starts on the right side, but about halfway (on 4" part ) it fades to about 50% power. This obviously ruins the part. With my tube machines this would be an indication of misalignment or Potentially the tube heating up. With these solid state lasers, are there potential heat issues to be aware of?

Again this exact issue happens with both my lasers now. Could it also potentially be the building power? Is a 50w machine actually drawing a ton of amps?

Since it occurs on both machines, I’d think it was software related… I run my 60W MOPA off a power strip with most of my other machines connected… so I doubt it’s a mains power issue.

Laser Everything has a video on checking your power supplies… I think I’d start there and ensure when it’s power drops, the supplies aren’t having an issue.

Good luck


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