E-Series Audio Interfaces (Excluding E8x8 Pre)
Verify that the USB cable is fully inserted, making sure to connect to the USB-C port on the device, not the POWER port.
Try connecting an additional DC 5V power supply to the POWER port.
Check that your operating system meets the requirements: macOS 12 or later, or Windows 10 or later.
The driver may not be installed correctly. Please refer to troubleshooting solution #1 (Control Center Displays "Please install the driver").
Check the USB cable for damage and try using a different cable no longer than 2 meters.
Try a different USB port on your computer, preferably one on the back of the tower.
If possible, try connecting the audio interface to a different computer or a mobile device to rule out a computer-specific issue.
Check if you are using a TS plug on the Line Out. The audio interface's line outputs are balanced. Using a TS cable will short the output signal, which can lead to abnormal behavior. Ensure you are using a TRS audio cable for a fully balanced connection.
E8x8 Pre
Check that the USB cable is fully inserted. There are two USB ports; either can be used, but if both are connected, the unit defaults to USB-1.
Confirm that the device is connected to power and has been switched on.
For further troubleshooting, please refer to the steps for the other E-Series audio interfaces above.