Mac doesn't recognize external drive

My Mac mini will not recognize the external drive I have been using for CDs - music, etc. It was working before the last update... help! thank you - please help in laymans terms - I only know enough to be dangerous - thx

 

Thank you for trying to help me. no, I do not have another mac. last update - when it updated to El Capitan. I went to utilities then clicked on disk utilities and it does not open - wheel keeps spinning and it says "Loading disks" but nothing shows on the screen but the spinning ball...Also - when I put the cable into my belkin hub it recognized it and said to plug it into the other for more power... so something recognized it... now I have a cd in the drive and no way to remove it if the mac won't recognize it...

 

Ty - we accomplished removing the cd from the unit. I restarted using Comm R and was shown my choices - I chose repair and the external showed along with the cd - I was able to eject the CD (yeah!). upon restart, the drive did not "show" when disk utility finally loaded.

 

The unit didn't show on the finder but when I reinserted the disc - voila! it worked. Rebooting and the Comm R repair did the trick. thank you very much. do you get points for this??

 

I liked them all -thank you for being especially helpful - what do you think of iExplorer? I want to save phone messages from my grandchildren but now my voicemail is 94% full..... is it safe to use?