You’ve put a disk expectanlty into your Superdrive. It doesn’t like it. The drive makes some rather weird noises as it spins, stops, spins and stops again before finally refusing to do anything. All is quiet. The disk is still in your Superdrive, but your Mac hasn’t even had the courtesy to mount an icon on your Desktop.
You try the eject button on your keyboard. Nothing happens. You consult the eject button on your menu bar (if, indeed, you have one) to see if it acknowledges the presence of the disk. It does not; as far your Mac’s concerned, there’s nothing in the drive. Nada, rien, zilch. Getting slightly annoyed you reboot in the hope that the disobliging disk will be expelled. Nope. Another period of funny noises and nothing doing. Now’s the time to take total control and sort this out once and for all. Open the Utilities folder (in Applications) and then open the Terminal.
Now type in the following:
Et voilà, the disk is expelled!
You might now wish to clean the disk and, if it still won’t mount, clean your Superdrive. If it still doesn’t work, try the disk in another Mac. I have some disks that my older Macs won’t read at all (although they work perfectly with the majority of my disks) but that my newer ones will. It’s one of those things. Of course you can always burn a copy of the disk or, if you have more than one Mac networked, use the Superdrive that will read the disk as a remote drive to access the data on the Mac with the Superdrive that won’t!