See Find how to service or repair your Mac.Ĭheck for missing software: Make sure you installed the latest software for your device. If you still can’t use a device with the port, your computer may need to be serviced. Wait about a minute, then plug it back into the power outlet and start up your computer. If you can’t use this device, shut down the computer and unplug it from the power outlet. If you can use the device after switching ports, connect another device to the first port. If you still can’t use the device, contact the manufacturer for more information.

If your computer has more than one USB port, switch the device’s cable to another port.

Check the power, port, and cable connections: Make sure the USB device is turned on and its cables are properly connected.