If a USB device doesn’t work with Mac
If a USB device isn’t working properly, make sure it’s connected to your computer correctly, plugged into a power outlet if it has a power lead, and any necessary software is installed.
Check power and cables: Make sure the USB device is turned on and its cables are properly connected.
Check for missing software: Make sure you installed the latest software for your device. Visit the manufacturer’s website for any updates.
Check the USB hub: If the device is connected to a USB hub, make sure the device and the hub are the same speed. Connect USB 3.0 SuperSpeed devices to a USB 3.0 SuperSpeed HUB, USB 2.0 Hi-Speed devices to a USB 2.0 Hi-Speed hub, and so on.
If the device doesn’t have a power cable and is plugged into another USB device that doesn’t have a power cable: Try plugging the device directly into your computer’s USB port
or into a USB device that does have a power cable. You might need to disconnect and reconnect the other device as well if it has stopped responding.If you have many devices connected to your Mac: Disconnect all USB devices except the device you’re testing, an Apple keyboard and an Apple mouse. Make sure that the device is connected directly to the computer, and that any hubs or extension cables are disconnected. If you can use the device now, the problem may be with one of the other USB devices or hubs you had connected to your computer. Try reconnecting them, one by one, to your computer. When you find the device causing the problem, review its documentation for further troubleshooting steps.
Verify that the device appears in System Information: On your Mac, choose Apple menu
> About This Mac. In the window that appears, click Overview, then click the System Report button.Open System Information for me
In the window that appears, see if the USB device is listed below Hardware in the list on the left. If the device appears but does not work, review the device’s documentation for further troubleshooting steps.
Restart apps: Quit and restart any apps that use the device.
Restart your Mac: Choose Apple menu > Restart.