New Laser Tube and Power Supply but still no laser?!

Hello, I came across this page while researching and decided this might be a good spot to ask for help. I just recently purchased a new to me 50w laser. I bought it off a couple who said it just needed a new laser tube. I thought nothing of that and decided to by the unit off them. I decided to buy it largely due to the fact that it had the Rudia controller I was looking for. I bought a new tube and wired it up when it arrived but still had no laser leaving the tube (by this point I had gone through 1 broken tube and 1 other tube which I suspected was shipped to me broken before this one). I bought a new power supply, as I had heard that these go bad often and just figured that might be the cause of my issues after all. However, once I swapped out the power supplies that didn’t help my situation. I try hitting the “pulse” button on my controller and the “test” button on the power supply but neither produced a laser. On the new laser power supply the fan turns and LED turns on (I only have one LED which turns on with the power supply, I do not have a second laser activated LED) so I suspect that the power supply is fine (I tested the old and the new power supply and both have the LEDs lighting up and the fans spinning)? I have a multi-meter and can test the power supply if I can find out what I am testing and what results I should get back. I am a high school student so I don’t have a whole lot of knowledge nor money to throw at this system to get it working. I suspect there might be something wrong with how the unit is grounded? If anyone has any helpful information or resources I’d love to get some help. I’ve been researching online for weeks to no resolve. I wanted to use this laser to start a business to help get me through college but I need it to cost less than college haha. I included pictures of the wiring, controller, and power supply of my unit in case that will help.

I’ve never heard of a safe way to check the output of a power supply. I’m sure it can be done but not with a multimeter. I’d say that If you give it power and it doesn’t glow then something is broken. Tubes are more likely to fail then power supplies.
Be very careful with the PS output. Keep the power low and coolant on if you test it.


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I have a slight suspicion that the power supply might be bad, after testing it on what could've been 2 fine tubes. I just find it hard to believe that my brand new power supply could be broken out of the box. I would like to be able to find out if it is bad for sure so I can get a replacement part sent if needed (Still in return period for the parts). Is there perhaps anything that might stop the laser from firing (like a safeguard or switch) when using the test button on the laser power supply?

Yes power supplies have standard terminals like ground +5v PWM. A control pin and water. Research how each signal works. You could drive the PS by applying the right signals to the pins which takes the controller out of the system. Find out how to create a voltage divider circuit for PWM and start around one volt. Too low and it won’t fire. Too high and you overdrive the tube.


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