Today I changed the USB ports that my Bose Companion 5 system is attached to and since then no sound. The sound control panel recognises the device as a Bose USB Audio unit, but claims there is no driver for it. I have tried all USB ports, including the original, I have cyled the power and restarted everything. Nada. How do I get out of this? I contacted Bose and they say they know nothing and that it must be an iMac problem...
Unplug the Bose and restart the computer after it fully loads plug the Bose back in and make sure it shows up as an sound output in your system prefs....
Thanks for your suggetsion. I rest the PRAM (twice) & it had no effect. I don't know if my My 24" iMac has a power manager, it's not designed for battery use.
Thanks for your suggestion. I turned everything off, left it overnight. Restarted with a PRAM reset & then reconnected the Bose equipment & powered it up. The Audio control panel shows "Bose USB Audio" but, under the setting for the selected device it says "The selected device has no driver" (approx. as the message is in German). It's all very frustrating.
Zapping the pram helped me too. I have the same problem. But: After a couple of reboots it is coming back. On your Mac too? What is this? I don´t want to go through this pram and powerdown-thing 3 times a day!