An Unknown USB Device is listed in Device Manager or device is not detected error occurs when a USB device is connected to the passthrough or hub on a monitor.

An Unknown USB Device is listed in Device Manager or a device is not detected error may occur when a USB device is connected to the passthrough or hub on a monitor for several reasons. Follow the procedure below to resolve the issue.

NOTE: Because each of these steps represents a possible solution to this issue, check the connectivity of the USB device after completing each step.

1. Power cycle the computer.
   • If you are using a desktop computer, follow the steps below:
     1. Remove the USB Device, turn off the computer and then disconnect the power cord.
     2. Wait at least 30 seconds, reconnect the power cord and then turn the computer back on.
     3. Plug the USB Device into the computer. Be sure to connect the USB cord or USB device per the device manufacturer instructions.
   • If you are using a notebook computer, follow the steps below:
     1. Remove the USB Device, turn off the computer, disconnect the computer AC Adaptor cord (if connected), and remove the computer battery.
     2. Wait at least 30 seconds and then re-insert the computer battery, reconnect the computer AC Adaptor cord (if necessary or desired), and turn it back on.
     3. Plug the USB Device into the computer. Be sure to connect the USB cord or USB device per the device manufacturer instructions.
2. Unplug the USB cable and power cord from the USB Device and then plug both cables back in. Be sure to connect the USB cord and USB device per the device manufacturer instructions.
3. This issue may occur if you are using a monitor with an integrated USB hub and do not have any USB device connected to the USB port on the monitor. Disconnect the USB cable between the computer and the monitor when you do not have a USB device connected to the monitor.
4. There may be an issue with the USB cable. Use a different cable to connect the USB device.
5. If the USB device is connected to a USB hub, it may not receive enough power to work properly and require a powered USB hub or must be connected directly to the computer. Consult the documentation for the USB device for information about power requirements.
6. Incorrect or outdated drivers for the USB device may be installed. Contact the manufacturer of the USB device or visit its Web site to obtain the latest drivers.