No connection between computer and laser, plz help

Sorry for my bad english but i need your help.

I have a hobby machine the Sculpfun s9 that I have enjoyed working with. Now I bought an extension so that I can engrave larger things, screw them together, swap cables, but now the machine no longer works.

Already tried the following:

  • another USB cable,
  • short cable back,
  • lightburn reinstalled,
  • another computer, nothing helps.

It keeps saying that the port com3 has been rejected. (on the other computer com4). Also tried other software. The laserGRBL also has its error message. Lightburn keeps saying ‘waiting for connection’. Who can help me please?



First, open device manager and check which COM port has been assigned to the laser. If there is none (no “usbserial” device), then the mainboard is not working. In that case, remove the cables you changed and try again with only USB and power connected. Does that work then?

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Thank you for your response. Took me a while to find someone who could explain to me where to find device manager. All steps done. Com3 was not included. I added this one. It seems that the computer now knows how to find the laser. But unfortunately, Lightburn still keeps saying “waiting for connection”. Any more tips I can try?

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