I having issues with an upgrade. I bought a couple of Lasertree modules. The small one is easy as it’s just a 5w 12v head. the adapter board runs fine, laser works as it should. The second one is a 24v 20w. I suspect the driver board is faulty. Can I bypass the driver board and apply the PWM line and external 24v power supply directly to the Laser Module? I can see the Lasertree connections are 24+ GND and PWM. Why do I need the driver board as well? The Neje used to connect directly to its original 12v laser module so I’m assuming that the PWM should be good so long as the new module is getting the right voltage? Or do these driver boards do something else, like convert the PWM signal, clean up the voltage or something?
Generally there are only three connections to the laser module, power, ground and pwm.
These driver boards do nothing except separate the boards +Vcc from the supply for the laser module.
I got a couple of these JL1 machines ($79 USD each). One of them I put on a 5.5W 40630 NEJE head the other remains stock with it’s 500mW laser module. You can see the conversion board in the lower right photo.
All the driver board does is make it easy for anyone, with no technical knowledge, to upgrade one of these. You can bypass it and run power to the head by itself. Some of these draw so much current they have paired the ground and power lines to handle more current to the module.
Many of these have a PWM input that stated as ttl compatible, but since 3.3V is above the high threshold, 3.3V boards will work for this without modification, but most of these 3.3V controllers won’t operate on higher voltages.
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Thank you. I agree. I just tested the 20w LaserTree module, bypassing the adapter. It still outputs ‘burning-power’ at rest with the PWM connected but no signals being sent from the PC. The 5w LaserTree moduleI have works fine with the machine so I know the PWM is good.
So it’s output is 100% anytime you have power?
You need to check the pwm that tells it when to lase.
Do you have a voltmeter you can read the pwm signal?
I do have a meter. However, I have another module from the same brand ‘LaserTree’ It’s only a 5 watt optical, however it works absolutely fine on the machine. If the PWM was bad, it should affect that module, especially as it’s the same Brand and their signal processing is likely to be compatible with each other. While I didn’t check the PWM voltage I did check the power supply to ensure that’s giving 24v, it is. I’ve asked them for a replacement as I think it’s just a duff module. I even tried sending a test stream from Lightburn. Of course it engraved, but everything was joined up as it did not stop burning.
You’re probably correct, if you have a test bench, you can put the module on the bench with just power/ground and see if it lases, it should not without a pwm signal.
Don’t look into the beam 
, point it at a wall.
Actually it doesn’t. With just the power connected it shows it’s pointer crosshairs and does not lase. It only misbehaves when the PWM is connected, either directly or through an adapter board. I have another machine, but it’s a brand new Atomstack. Litterally a couple of days old. I don’t have the appetite to take a feed off it at all even though it is a 24v 20watt machine. So I’ve left the original machine configured with the 5 watt and asked for a replacement head. Spent enough time mucking around.
If it does not lase with just power, that would indicate a problem with the pwm from the controller. Can you measure that with your voltmeter?
At 50% pwm, it should read 50% of the machines voltage. A 5V output would read 2.5V and a 3.3V maximum voltage output would be about 1.65V.
It sounds like it’s stuck at full output.
I agree, but I am guessing it is a wiring error.
I do not have anything open in front of me ,but the laser is a 2-wire device. Apply power and it lights up. The adapter board (it may be built into the laser module that has 3 pins) is a 3-wire device. Besides power, it has a 5v TTL input to control the voltage to the laser module. The other two wires are the fan.
@jkwilborn provided pictures of his, but we cannot see yours. Maybe a few closeup pix will help.