I have a new 50 watt laser tube with a 60 watt power supply, the tube glows and it’s pulling 22 milliamps but there is no output. The tube i replaced did the same thing and I thought the tube might be bad so I replaced it. It’s not that the mirrors are out of alignment, I can put a piece of paper over the end of the tube and nothing happens. Is it possible that I missed something in the software settings? I’m running an older version of LB 1.7.00.
Help!
Pictures are worth a kiloword here: take some good pix of both ends of the tube so we can look over your shoulder.
While these possibilities may seem absurd, it’s worth eliminating the absurd:
- Is there a cover over the exit end of the tube, perhaps tucked into the rim of the water-cooled fitting?
- Is a foreign object / spider roasting in there?
- Is the tube mounted backwards, with the beam coming out the other end?
Although LightBurn has no settings that can make the tube lase at full power without emitting a beam, it may be worthwhile to test the HV power supply without involving the controller:
- Unplug the connector carrying the controller signals
- Put a target at Mirror 1
- Push the
Testbutton on the HV power supply - The tube should fire as long as you hold the button down
Upload the pix and let us know what you find.
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Is this an analog meter in the cathode or the a digital lps reading?
I don’t know about the Trocen, but my Ruida controller console pulses at whatever the maximum power is set. If it’s set for 99%, that’s where it will laser on a pulse.
If you unplug the signal connector (green) to the lps and press the test button (red), then they lase at 100%.
I doubt you can install it reversed. The cathode wire is very low voltage and I suspect the hv would punch through the insulation, if reversed, before the tubes trigger voltage is reached.
- tube is glowing
- drawing 22mA
- no output at end of tube
My suspicions are that it’s lasing. Why nothings coming out, I have no clue. It would have to be broken internally. Unlikely that you got a pair of tube with that issue.
There is no way to cause a tube to glow with excitation, draw lots of current and not produce a beam of any kind via the settings. That energy is going somewhere.
Follow @ednisley suggestions they are a logical path.
Thanks for the answers, I think I figured it out, I didn’t mention that my machine has been in storage for a few years, along with the unused “New tube”. I checked the date of manufacture of the first tube and it was 2017. I’m not sure of the “New tube” but iwas amybe a couple of years newer. Frome what I’ve read, the tubes are well beyond their shelf life and the co2 has leaked out leaving the remaining gas that still glows when powered up. I have a 60 watt power supply so i ordered a new larger 60 watt tube. I’ll let you if this solves the problem. Thanks again.
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That’s useful information!
The rule of thumb I’ve seen says to not store a tube for more than a year, so eight years is definitely too long. 
I suppose you could use them as terribly inefficient night lights … 