Weird laser connectons

Machine: _ full spectrum laser_

Board: Cohesion3d LaserBoard v1.0

Firmware: _ "I have a new board and I’m using whatever it came with!_

Problem/ Question: I have everything hooked up and I can move the gantry home etc, but the last problem is getting the laser to fire.

I have been doing a lot of reading and I get how it’s supposed to be hooked up but I think my laser power supply has different pinouts from the standard pinout I see online. (The power supply has absolutely no markings identifying the pins)

Laser Power Supply Model from label: MY JG80W EKR0421
Standard pinout from web:

Original Wiring:

Probed connections:


Other observations:
-Test button on the power supply does fire the laser.
-Grounding the 5v and hooking up the yellow wire to laser fire on the smoothie board causes the laser to fire weakly (I did this by accident following connection diagrams on the web) (the green light also glows dimly)
Has anyone come across this before or have any troubleshooting ideas?


A few more pics of the entire machine, full LPSU… would help. Show me everything.

Which FSL machine is this? 80w suggests something large and not desktop sized.

Here you go see pics below. Yes, it’s a large laser, it’s an FS professional 36x24 we bought in 2012.

Ignore the connections coming out of the Cohesion3d board. That cable is different than the one thats currently plugged into the laser supply. I attached that cable so I could do the connections and probe things without having to climb around the back of the laser cutter over and over again. Our shop is a little tight.

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I have been googling for a different wiring diagram for days now, with no results matching having a 5v pin where mine is.

In my research I found that laser tubes should only last 2.5 years at the most. Is that what people normally get out of theirs? Ours is around 7 years old. It had definitely lost power over the years but we have still been using it, until the FullSpectrum board instituted some sort of firmware licensing error that they said they might be able to fix for $100.

We also do mostly vector cutting and we wouldn’t mind having a little more power.

The cohesion3d board is working great other wise. Its much faster then the board that FullSpectrum had installed.

I’ve been pondering this for a bit and I have a few possible outcomes that I can elaborate on, but I’m also a bit confused, in a close up pic I see no wires coming out of 5V on the LPSU, but then in further pics I see a brown wire. So do we know where it goes?

Here are the options we can explore:

Put in a POT between Gnd, IN, and 5v, use it to set the tube to max power (80% ish) or other max, as explained here: Cohesion3D PWM Control and Potentiometer vs 'Digital Panel'. Then L from the C3D drives the LPSU via TL/ L/ LaserFire, whatever name the active low thing there is.

Forget the pot and just bridge IN to 5v. This means 100% power in LightBurn can set your tube to max power and fry it nice and early for you. There are ways of capping this in config, but still.

I also recently learned about another configuration option:

laser_module_ttl_pin 1.30 This pin turns on when the laser turns on, and off when the laser turns off.

This would allow us to mirror how the DSP’s control the LPSU.
When I started doing laser controllers we did a 2 wire configuration like this which was not ideal on a K40 (since there is already a pot and test fire button in play on the panel) but in your case it might be worth considering.

Let me know if you want to try that out, I’ve never used it before, and I’ll walk you through some stuff.

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