Laser tube firing

I bought a w4 100w reci tube and power supply and did and upgrade to my machine when my last tube broke. I installed it and it is firing but my problem is that the tube starts firing as soon as I turn the machine on, I have no control with the on/off switch of the laser tube, did anybody has any idea of what is going on? Thank you.

First, you need to know the working principle of laser tube: controller sends a signal to power supply, then power supply sends out current after receiving the signal, and the laser tube receives the current and generates laser.
So you can check from the main control board, laser power supply, and signal transmission line

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Thanks with your help I will try that

Depending on the controller it can be wired in a coupleof different ways. No idea what type of controller you have.

There are two control signals to the lps (laser power supply or the tubes high voltage supply).

The pwm controls lps current and is wired to the IN terminal of the lps.

The other control line is Laser Enable (L-On using a Ruida). This tells it to lase at whatever current is set by the IN signal… if this is stuck low it will be enabled.

If it’s not a dsp type controller…

If you have a pot to set current, it’s wiper goes to IN and the pwm goes to H of the lps.

The laser switch may do this in more than one way, but they can be wired to the P terminal of the lps.

You need to be more specific about what machine you have and especially the type of controller…

These signals can be measured by a mulitmeter with no problem.

If you wired the lps correctly, it should not be enabled during boot…

I’m speculating that you have either incorrectly wired the replacement lps or it’s faulty. There is the possibility that you have a bad controller, but I doubt that.

Good luck


Thanks for your help

Did it make sense to you?

What kind of controller does it have?

Do you have a knob to set the tube current?

Sing out if you have issues.

Good luck


Thanks for your help everything is working fine.

How did you fix it?


I rewired it like you say and work, thanks.