How to troubleshoot connection issues with USB

A very common problem with Windows systems and lasers is the way Windows handles USB connections - If it thinks a connection is idle, it can put the port into a power-save mode, which can make your device stop talking to it. This is especially common with laptops.

If you are having issues where you often lose the USB connection after a period of time, try the following:

Windows 7:

Windows 10:

It’s also worth noting that USB cables are limited to 5 meters (16 feet). If your cable is longer than that, you may have transmission errors or connection problems unless the cable is “active” - IE, re-transmits or amplifies the signal, and plugs into a power adapter.

Other common problems:

  • poor grounding causes electrical noise
  • chiller or air compressor on the same circuit as the controller can cause electrical noise or brownouts

If you are using a GCode device with “Home on Startup” enabled, USB connection errors will cause the connect to re-establish, and the device will re-home. This is a very good indication that you have one of the above issues.