My USB Devices isn't "talking" to my Mac, what is... (by 4 users)

If your Mac isn't talking to your Universal Serial Bus (USB) peripherals or your peripherals aren't talking back, here's how to open channels of communication.
1. Open the Apple menu and choose Apple System Profiler (ASP). ASP 2.1.2 and higher lists all USB devices that are connected to your Mac. If ASP sees the device, your problem is software-related. If it doesn't, then your device may need service.
2. Check Apple's Web site (see Related Sites) for USB firmware updates.
3. Try unplugging and replugging the USB cable for the troublesome device. If you have an alternate USB cable, try that next.
4. Restart your Mac while holding down the Shift key (this disables non-Apple extensions). Try the device again. If it works, you have a faulty extension for that device (and don't need it).
5. If the device still doesn't work, verify that its driver software is installed and active. If it is, but the device doesn't work, reinstall the driver software.