After a year of happiness with no problems, my board just quit

Machine: _K40

Board: _Laserboard

Firmware: _Smoothie

Problem/ Question: _I have been running my K40 with the Laserboard and Lightburn for about a year with zero problems. Yesterday I was running a job and the laser head just froze. I looked at GLCD and it was froze too. I tried to move the head manually but the stepper motors were energized so they were froze too. I powered everything off then on again and restarted the job. After a while everything froze again but this time the LCD screen went blank but it was still lit up. I went to power off then on again but now I get nothing. The LCD screen lights up but its blank. The stepper motors are energized and I still get the USB connection sound from the windows 10 computer but Lightburn wont connect anymore. I was thinking maybe a corrupted SD card, so I got another card and formatted it and put a BU copy of the stock firmware file and config text on it and stuck it in. Nothing happened. LCD lit up no text and frozen stepper motors. This all happened out of the blue after a year of no problems. Nothing at all has changed on my setup whatsoever. I did notice that after I took the second SD card out and looked at the files that it still had the firmware.bin file on it like it didn’t upload the firmware and change the .bin to .cur or whatever. Like the board is not initializing far enough to load the firmware. I have two center lights blinking simultaneously which It never did. Usually those two lights are blinking back and forth but not together. Did my board give up on me after a year of blissful happiness? I have never had anything but perfection out of this board but now I’m sad! Does anyone know what I can try to get my board running again?

Did you provide those pictures? We need pictures to understand your setup!

OK after messing with it some more I see the L2 and L3 lights blinking together. It was hard to see but apparently they do blink together under normal operation. All other lights are lit solid. It still wont take the firmware (no blinking lights either) but i guess since firmware is already on it, it doesn’t need to load it again? Now the stepper motors are energized but when I pulled the stepper motor cable off, I lose USB connection. I didnt think that was good so I didnt do that again. I can test fire the laser just fine. Lightburn says I’m connected but it doesn’t home at startup and i can move the head from the software. I am using the 24v power supply that I got when I bought the laserboard, but is it possible that my main PSU went bad even though I can still fire the laser? There are 4 blue wires coming from the main PSU to the laserboard. What are these for and could this be the problem? But why is the GLCD lit but not showing anything? I’m at a loss…

I installed my old Nano board to see and everything works fine with the stock board. Now what? Can my Laserboard be repaired?

This is it. I uploaded this photo just in case it will help. I really hope I can get some help. I refuse to go back to the nano board and I refuse to use anything else but Cohesion Laserboards!

Hi Mike,

We hate to hear about your issues regarding the board and GLCD not functioning as expected. I know you have attempted several approaches, but I want to walk through this together to determine the root cause.

With the machine off, we recommend labeling and taking clear photos of all of your wiring, and unplugging all of the connectors from the LaserBoard, as well as disconnecting the USB and power brick. Allow it to sit for a few hours or overnight.

To determine if the card is or is not being read, unplug everything and with no memory card, plug in the LaserBoard power supply. Wait 30-60 seconds. Which LED sequence are you getting? For reference:

Please confirm if this is where you obtained the latest files to reflash the card?

Reformat and flash the memory card again. Provide a screenshot of the contents of the memory card after flashing. This will help us confirm that the files are updating correctly.

Power down and add the freshly updated memory card. Power it back on and report back which LED sequence you are now getting with the card in place.

Do you get the same results if you try these steps with multiple memory cards?

Is that a stray bare wire next to the Ethernet connector?


Good eyes. It scared me for a minute. No that’s just a dried strand of hot glue I used to secure the connector. Whew!

I’m about to go through the diagnostic steps that Starla suggested…

I am getting VMOT led ON, 3v3 led ON, L4 led OFF, L3 led fast flashing, L2 led fast flashing, L1 led ON. There is a Play led at the top right corner of the board that is ON as well.

I did get the files to reflash the card from the link you provided.

The files seemed to flash. I got the loading firmware lights then they went to normal operation. The card now lists a firmware.cur file instead of .bin so that tells me it flashed.

I am going to try with multiple cards now…

Hi Mike,

Thanks for the additional information.

Based on this, it sounds like your board is reading the freshly flashed SD card and behaving as expected.

Once again, disconnect everything, including the board PSU.

There is a jumper above the row of external stepper connectors, towards the center of the board. It is labeled “5vREG or USB”. Temporarily, shift the jumper to the USB position (move it from connecting the left 2 pins over to connecting the right 2 pins).


Insert the card. Connect the USB cable to your LaserBoard. When you plug it into your computer, do you hear a “ding”? Confirm if it is recognized and shows up in the device manager / “Devices and Printers”?

Report back with the results. Before proceeding, move the jumper back to the “5vREG” position when you are done with this quick test.

I did hear the ding and the laser started to home but then stopped again just like it did before. At least i know we have communication going. Is there a way to use wifi with the board? I see connections for it…

Hi Mike,

Thanks for your patience over the weekend and for confirming the results. This is a good sign as movement, homing initiation, and communication with the computer means the board is not dead.

Regarding the homing issue, please provide a link to a video of the sequence which occurs.

It sounds like this is happening every time based on what you have reported previously. Can you confirm? Have there been any recent changes to your environment around the time when the issue started? (e.g., new appliances, electrical wiring changes, etc.)

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