When inserting blank media into the super drive , it is not recognised. Also when a playable disc is erased, it then becomes unrecognised.
Can anyone suggest any remedies. Thanks.

As long as you are using Disk Utility (located in the
Utilities folder within the Application folder on the hard
drive) you should be able to erase an erasable disk (CD-R/
W for example) and use it again.

As for the blank media not being recognized I have two
possiblilities to suggest. First is that the disks themselves
might not be recognizable on any Macintosh computer.
Try verifying this on another machine. Second, if they
have worked before and aren't now or if they work on
another machine then you might have your system set to
ignore these. That is easy to change. Navigate to
Macintosh HD->Applications->System Preferences or
click on the Apple symbol in the top left and choose
"System Preferences..." there to lauch this application. In
the panel that says CD/DVD or something like that there
are options as to what your computer should do upon
inserting blank media. It might be set here to ignore any
disks inserted.

Good luck!