USB Dropouts and Brownouts

You are here:

USB issues may present with the following symptoms:

  • Jobs stopping in the middle of running or showing busy status
  • USB device disconnects or reconnects with messages/sounds on the computer and/or in LightBurn
  • Light and dark banding on image engraving (raster scan/fill)

Troubleshooting Steps:

  1. Use a data only, high quality, shielded USB cable to prevent potential communication issues. The blue cable that comes with most of these types of lasers is not typically reliable.
  2. Longer USB cables have also been known to cause issues, so try a shorter one (less than 16 feet). Make sure the cable is fully seated at each end. Avoid using USB extenders, as they may be susceptible to interference.
  3. Check that your machine is properly grounded and that the laser power supply is grounded to the chassis.
  4. Move any potential EMI or RF emitting devices away from the board, including the high voltage wire for the laser tube.
  5. Ensure that your computer is not set to go into sleep/screen saver mode.
  6. Check that your USB ports are not going into power save mode. For Windows, this can be updated in the Device Manager by editing the Properties for the USB port being used or it can be disabled globally in Power Options by editing the Advanced USB settings. Windows updates can reset power save mode, which means it may need to be re-enabled.
  7. Updates can also cause issues with USB drivers, so confirm that yours are the most current: https://cohesion3d.com/knowledgebase/installing-smoothie-drivers-and-knowing-whether-you-need-to/
  8. For Mac, ensure that your USB port is not getting tied up by multiple drivers: https://superuser.com/questions/1135730/how-to-release-reset-serial-port-ftdi-devices-mac-osx 
  9. Try isolating the board on a different outlet or circuit in your home to see if it improves. It may need to be separated from where the machine, computer, chiller, air compressor, or any other appliances are connected, which could cause interference or put a load on the circuit and cause power dips. You may also consider using a power surge, ferrite cores, or a line conditioner if your electrical wiring is in question.
  10. Try connect the USB cable via a powered USB Hub.
  11. If you have the GLCD, try disconnecting to see if the issue persists.