Clarification on power wiring

Machine: K40 with v3.3 moshi

Board: laserboard

Firmware: Smoothie or GRBL-LPC? “I have a new board and I’m using whatever it came with” is also a great answer! Not there yet

Problem/ Question: hi guys! New to the world of lasers. Got a killer deal on a K40 but after getting into it I realized why. It’s brand new, but must be a really early model. I can’t find any info on the controller so I’ve opted to just ditch it from the start.

New laserboard is on the way and I have a pretty good idea of what needs to happen when it gets here

. Only question I have at the moment is the power wiring.

I have a 6 pin connector with 5 wires. Two grounds, two 5v and one 24v. I know you need a ground and the laser 24v, but how do I determine if my 24v is the right one?

Pics for reference. On the connector I colored, black is ground, 24v is blue and 5v is red

Hoping to get some info on this power wire. Is this a unique setup? I’ve searched for hours using every search term I could think of and I have found no resolution on my own.


There are a handful of useful threads when searching this forum for “moshi”:

It would have helped for you to keep the cables plugged into the stock board and get some pictures of that so you (and we) know what you are working from.

But yeah, I haven’t seen this particular combination of components before.

All the LaserBoard will need is a Ground and a Laser Fire signal. No 24v and no 5v.

Then the 2 motors, and endstops. Your pics don’t show what your other wiring looks like for those.

The exposed Laser Power Supply suggests that this is an old machine. It might not respond to power control from the C3D board as well as the “new” enclosed LPSU’s do. Keep that in mind.

I apologize. I had a half dozen or so pics I tried to post and was not able to, so I kept it to the power wire that I am unsure of.

So I guess what I need to know is how to determine which wire is my laser signal wire then.

I plan to upgrade the power supply. At this point I just want to get some sort of use out of the machine so I can justify the $500 I’m into it. It had an old moshi card I was never able to use. The machine has been a paperweight, I was hoping the laserboard was gonna be the upgrade I needed to get it going. Now I’m hoping I didn’t just buy another paperweight to go in the machine that is already useless at this point.

Got it! Spent a few hours with a meter tracing things down and figured out what I needed to do for my machine. Ended up being the ground wire and “5v” wire that are next to each other. That sub board acts almost like a relay to fire the laser

Glad to see its not a paper weight any longer. Happy lasering.