Disappointed with the latest Mac Mini offerings, I recently purchased a new 2012 Mac Mini core I7 with a 1TB hard drive. I then installed a 500GB Samsung Evo 850 SSB to use as the operating system disk, planning to leave the original 1TB hard drive installed as slower mass storage for MP3's, video files, etc. The installed OS was OSX Mavericks; I successfully used Super Duper to copy the OS to the SSD. I then booted up on the SSD, and once I had determined that everything was working correctly I upgraded the OS to OSX Yosemite 10.10.3. However, after I apparently successfully set up Time Machine to use with an external hard drive, I discovered that Time Machine is apparently not working correctly. When I access the Time Machine window it opens and shows the desktop, but when I click on anything nothing works. However, when I access the backup files on the hard drive itself in Finder everything appears to be there and is accessible. I can't tell if this is a Time Machine issue with Yosemite (I think I've seen references to this online) or has something to do with my use of a 3rd party SSD. I have an older Mini running Yosemite with only the original hard drive installed and Time Machine appears to work just fine on that machine. Any insight into correcting this problem will be most appreciated.