USB Dropouts and Brownouts

USB issues may present with the following symptoms:

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

Troubleshooting Steps:

  1. Ensure that your computer is not set to go into sleep/screen saver mode.
  2. 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 reenabled.
  3. Updates can also cause issues with USB drivers, so confirm that yours are the most current: https://www.ftdichip.com/Drivers/VCP.htm
  4. 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
  5. Use a data only high quality, shielded USB cable to prevent potential communication issues. Longer USB cables have also been known to cause issues, so try a shorter one.
  6. Isolate your machine on a different circuit from any other appliances. You may also consider using a power surge or line conditioner if your electrical wiring is in question.
  7. Connect the USB cable via a powered USB Hub.
  8. Check that your machine is properly grounded to the chassis.
  9. Move any potential EMI or RF emitting devices away from the board and/or apply ferrite beads to cables to reduce noise.
  10. If you have the GLCD, try disconnecting to see if the issue persists.
  11. If none of the above works, try the GRBL-LPC firmware: GRBL-LPC for Cohesion3D LaserBoard
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