Check your device’s FireWire connection to Mac
If a FireWire device isn’t working properly, it might not be correctly connected to your computer.
If your computer has more than one FireWire port: Switch the device’s cable to another port. If you still can’t use the device, contact the manufacturer for more information.
If you can use the device after switching ports, connect another device to the first port. If you can’t use this device, shut down the computer and unplug it from the power outlet. Wait about a minute, then plug it back into the power outlet and start up your computer.
If you still can’t use a device with the port, your Mac may need to be serviced. See Find out how to service or repair your Mac.
If the device is connected to a FireWire hub: Make sure the device and the hub are the same speed. For example, connect a FireWire 800 printer to a FireWire 800 hub.
If more than one device is connected to the FireWire port: Disconnect all other devices. Connect the device directly to the computer without using FireWire hubs or extension cables.
If you can use your device now, there may be a problem with one of the other devices. Try reconnecting the other devices, hubs and extension cables to your computer, one by one. When you find the device causing the problem, review its documentation for further troubleshooting steps.