24V from Laser PSU needed?

Machine: K40 with M2 Nano

Board: Laserboard

Firmware: Smoothie

I changed out the stock M2 Nano for a C3D Laserboard last year and have been very happy with it.

Now I’m doing some additional mods and a general rewire with terminals and improved wiring practice as part of that and it occurs to me to wonder if the Laserboard actually needs the +24V in the 4-wire harness to the laser PSU. (JST 4-pin VH3.96 latching connector) That was the actual board power for the Nano, but the LB is designed to be plug compatible, so maybe it’s just there because it was on the connector and not really needed?

I’m running the LB from an external 200W 24V supply, and would like to wire the entire laser as if it were designed from scratch and wired accordingly, which would mean deleting the 24V wire if not actually used. I’m definitely never putting the Nano back in, so…

Just needs L and Gnd in that harness.

Thank you! Hope you feel better!

Thanks. Still a bit of headaches and low energy but much better since last week, and trying to get back to work. I have been very productive at watching Brooklyn Nine Nine this past time.

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Are you sure I don’t at least need the 5V? I removed the +24 (Position 1 / far left on the PSU plug) and 5V (position 3), leaving GND (position 2) and L (position 4), and Windows and Lightburn no longer detect the Smothieboard.

PSU still fires in test, Smoothie lights up on power (green blinks then solid, plus red).

Well if you’re not using our power brick and doing things differently, then things will be different, but no the board does not need a 5v source. Show pictures.

Connection at PSU

Connection at Laserboard

Tried again this morning but still nothing. Also tried new USB cable. No joy.

Still no. Any ideas? I’m not using your power brick, I’m using your power input terminals.

In this picture the LaserBoard has absolutely no lights on, so I would suggest investigating how you are powering the board - whatever that power supply is and the blue/ white wires going to the power input screw terminal on the C3D board.

No, that picture taken with no power (the glare from the red light was too much if taken with it on). The actual light state under power is as described in the previous post (green blinks then solid, plus red) The power supply checks out at approx 24.1V.

The board appears to be working normally except for not being able to detect it via USB. You hear and feel the steppers get a bit of current when the board powers on. The laser PSU works normally from the panel controls. Manual on, the laser comes on and tube current modulates normally by turning the pot.

We have a new USB cable, and have checked numerous ports on the normal computer plus tried with another computer but cannot detect on USB.

Have you tried a new/ different SD Card flashed with fresh files?

Latest firmware from here:

Config from here:

Oh, I think your ethernet module is plugged in backwards here. Remove it and try again.

Abundance of clarity is always good.

Have you tried a new/ different SD Card flashed with fresh files?

Not yet, but did mean to add in this morning’s post that I reviewed at least the config file and it appeared not to have been corrupted.

Will see if I can find another SD card and load with fresh firmware plus new stock config plus my slight config modifications (X and Y steps per mm, and Y bed size / home position). If not, will just reload existing card.

Oh, I think your ethernet module is plugged in backwards here. Remove it and try again.

Yeah, I did notice that and correct it. I had taken it out while doing the wiring and put it back in backwards. Symptoms are the same without the Ethernet and with it installed (in either orientation).

OK, new SD card with current firmware and config files. Green LEDs count off in binary on first boot, then no further changes in symptoms.

Still not detectable via USB.

Have you tried a second computer? What OS are you running?

Have you tried a second computer?

And a third.

What OS are you running?

  1. Normal Lightburn machine (Win 7 64-bit SP1). Been working fine since last year till I did this wiring work.
  2. Second Win 7 machine. No drivers installed, but would expect to see an unknown device on device manager. Nothing.
  3. A Windows 10 box. No drivers specifically installed, but Smoothie claims Win 10 is plug and play as shipped, no driver installation required.

Well, you did what I was going to suggest - seeing if there’s an unknown device or something new enumerated that wasn’t there before. Check the underside of the board for damage around the USB connector / broken solder joints, etc.

The microcontroller seems to be getting power if it successfully flashes/behaves otherwise.

You have the ethernet adapter - can you access the board via ethernet? (just curious - it won’t actually do you any good since lightburn won’t talk to it over ethernet).

You have the ethernet adapter - can you access the board via ethernet? (just curious - it won’t actually do you any good since lightburn won’t talk to it over ethernet).

That’s an interesting, and as it turns out, prescient question. I have some small pressing jobs and I was hoping to at least be able to output from Lightburn to a file, upload to the Laserboard, and engrave straight from the board, assuming I can do it from the web interface. I don’t have the LCD. Not ideal, but acceptable as a short term solution.

So I hook up to the Ethernet, move the head around, etc., whatever you can do from the web interface, then armed with the knowledge that it still works, set off to find out how to save files from Lightburn and find out if I can engrave using the web interface.

So get this – all of a sudden I can see the Laserboard, AND the drivers are still working. All I did was hook up to and use the Ethernet, I swear! Then, thinking that maybe having having the Ethernet hooked up created a ground path or something (shouldn’t, it’s isolated and differential anyway), I unplugged the Ethernet to see if the USB quit again, but it still works.

Oh well, it broke itself, only fitting it should fix itself!

Thanks Ray and loather for trying to help figure it out!