Installation and configuration guide...
The DisplayLink USB Video Driver is required to configure an external monitor through a USB 3.0 port on the back of the iMac.
Important: External USB Video Adapters must be connected directly to an independent USB connection on the iMac. Connecting it to a hub, or even a powered hub can yield unexpected results.
DisplayLink USB Video Driver Setup
- Install latest non-beta version. Download here
- Restart.
- Install j5Create Driver v2.18.1101 (as of 4/19/2018).
- Restart.
- Connect j5Create USB to HDMI Adapter and Monitor
- System will automatically put everything in Mirror mode. Uncheck Mirror mode in System Preference –> Displays –> Arrangement.
- Confirm Display Layout.