Rambo laser pin

I have a laser diode that I want to use with my Rambo 1.4 board. It works with either the fan controller or TTL. It works with the fan port but it is pretty high power (15w output) and I am worried about it being too much for the fan port, I think that’s how I ruined my last board. I am fine with either using the heated bed port because it is higher current, or using a 5v pin with TTL. I would like to just change the firmware to use those pins for the fan control so it is easier to make gcode. How should I do that?

If you’re using the fan port as a PWM signal, it doesn’t take any current. Are you powering it from 12V outside of the rambo? Straight to the power supply?

You can change the pins.h file to swap the fin and bed pins. Then the bed mosfet will be used for the fan controls, so M106 would then control the bed pins. But I doubt that will matter if it’s just a PWM output.

No, there is no other power supply. My laser has 3 wires red black and yellow, I have been using it by just putting the red and black wires for + and - for the fan. I don’t know if that is the way its supposed to be set up but it has worked for me. This worked on my old board Archim2 but shortly after the fan mosfet stopped working so I upgraded to a rambo. I have tested the laser the same way on the rambo on really low power and it works but I don’t want to ruin another board. I looked in the pins.h file and found the fan and bed heater port but they both (and all other ones) have -1 after them. How can I swap them?

I’m only half paying attention, but I think it id the 8 and the 3.

I would guess the red and black should go straight to the 12V PSU and the yellow should go to the control pin. If it can handle 12V, then that can be the fan. But if not, then you can put it on a 5V pin (IIRC, 45 is good on the rambo?).

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To switch to the 5v pin I would just change the fan_pin from 8 to 45, is that correct? and then where on the board would that pin be?

I’m not sure where I got this diagram/image…somewhere on the forum I think: