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Troubleshooting

Connection Issues

Status Shows Setup Required

No connection has been saved yet. Run the wizard from Settings → General → Run setup wizard, or open Settings → General → CNC Connection Setup, choose the connection and click Save & connect. See First Connection.

Controller Not Detected

  • Ensure the USB cable supports data (not charge-only)
  • Check that the correct drivers are installed for your board's USB chip (CH340, CP2102, etc.)
  • Try a different USB port
  • Pick the port by name: Settings → General → CNC Connection Setup → Serial port

Wrong Device Connected, or Board Skipped

Auto-detect only tries ports that look like a CNC controller. It skips:

  • Bluetooth ports
  • Debug console ports
  • DJI controller ports
  • ncSender Accessories (pendant, Wireless USB)
  • Ports whose USB chip does not look like a CNC board

If your controller is skipped, open Settings → General → CNC Connection Setup and pick its port by name under Serial port.

Alarm on Connect, or Unlock Keeps Retrying

The controller is in an alarm and refuses to unlock while the cause is still active. See the FAQ:

Disconnects After a Reset, or a Job Stalls on Wireless USB

Older versions could drop the connection when the controller sent garbled data, for example after a reset during a motor fault alarm. A job could also stall when the Wireless USB stopped accepting data. Both are fixed. Update ncSender to the latest version.

Visualizer Issues

G-Code Not Rendering

  • Ensure the file is valid G-code
  • Very large files (>1M lines) may take time to parse
  • Check the Terminal for parsing errors

Accessories

Pendant or Wireless USB not found, not activated, or needs a firmware update: open Accessories from the toolbar. See Wireless USB and Pendant.

Updates

An update did not install, or Windows blocked the installer: see If an Update Fails. Many older problems are already fixed, so update to the latest version first.

Performance

Slow UI on Linux

Getting Help