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1. Clean the SuperDrive’s slot with compressed gas/ Vaccum Cleaner

Your CD / DVD drive on your Mac might have got dust in its lens so clean the dust out. I bought this air duster Ecola Vacuum Cleaner ( for Keyboard,Notebook,Computer,Car etc. Compressed Air Duster ) just for $15 from Amazon, It can vacuum out dust and dirt from the chink of the keypad of calculator,telephone,computer,car and so on so give it a good spray into the CD / DVD drive slot on your Mac and this will resolve the problem.To do this first Shutdown your computer and get a can of compressed air. Place the tip of the nozzle attachement where it is aiming inside the drive and give it a couple of quick blasts to blow out any dust particles that may be causing you issue. Power up the system and give it another try.

2. Reset the NVRAM/PRAM and SMC

A small amount of your computer’s memory, called “non-volatile random-access memory” or NVRAM, stores certain settings in a location that OS X can access quickly. The settings that are stored in NVRAM depend on the type of Mac you're using, and the types of devices connected to it.
Power related settings can be controlled by the System Management Controller (SMC) on your Mac. If you are experiencing issues with powering on your computer, sleep, wake, charging your Mac notebook battery, or other power-related symptoms, you might need to reset the SMC instead.

you can find reset instructions for both here:

Reset NVRAM and PRAM. - Shut down the computer.
Holding down the Command(Apple), Option, P, and R and then hold the Power button simultaneously, and told me to do that 3 times and wait for 3 loud buzzing (or some odd sound I can't describe).

Resetting the System Management Controller (SMC).
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3. Delete the following configuration file to create a fresh copy


Your Mac store the information of the every CD you put into the CD / DVD drive in a file called CD Info.cidb.Similarly some other files contains info about the settings and configuration of the drive and disk.Deleting them will allow OS X to create a fresh copy of them.Delete the following files from your Mac.
~/Library/Caches (your local Library directory).
System/Library/extensions.kextcache.
/System/Library/Extensions.mkext.
/System/Library/Caches/com.apple.kernelcaches (a directory).
/System/Library/Caches/com.apple.romextensions (a directory).
CD Info.cidb (from ~Home/Library/Preferences).

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