Thank-you GTA Fan, this seems to have done the trick. I tried all of the following, but my laptop only started reading blank cds consistently after your tip using Terminal and pushing the CD back in. For some reason that has worked. Thank-you!!!
- Holding down shift, control and option while rebooting didn't work (resetting SMC)
- Rebooting holding down C with a CD inside (that helped my laptop identify a blank cd for the first time but when I ejected it and tried a new blank disc it went back to its old tricks of spinning and whining then spitting the cd out)
- Holding down shift while rebooting and using Disk Utility didn't work as it didn't recognise the blank cd when in safe mode
- I couldn't download firmware, a pop up box kept telling me I don't need it and wouldn't let me go further down the installation process
I have a Macbook Pro Mid 2009 laptop and I have a superdrive that could read and write DVD and CDs, and since upgrading to Yosemite I had problems reading blank CDs only; all other functions were working and it would be hit or miss when I could burn a CD because the blank CD wouldn't mount and my laptop spat it out after spinning and whirring for a minute or two. I tried Imation and Verbatim, both with the same result; I could read CDs and DVDs that I have burnt previously as well as commercially bought CDs and DVDs and I am certain this is not a physical fault with the drive but something to do with the upgrade. When I called Apple Support they couldn't tell me what was wrong and hadn't heard of these issues with Yosemite, so I also have a genius bar appointment but I don't think I need it now. I will monitor it now and will feed this terminal advice back to Apple because I think they need to know about this, such a nightmare when it happens to you.