Q: mirroring works on iOS but not iMac. My iMac is late 2013 and running Mavericks 10.9.2  I can view photos from my iPhoto library thru iTunes as well as videos but the mirroring shows a blank screen on my TV.  Works fine with iPad .  HELP!

Mirroring works on iOS but not iMac. My iMac is late 2013 and running Mavericks 10.9.2  I can view photos from my iPhoto library thru iTunes as well as videos but the mirroring shows a blank screen on my TV.  Strangely, the mirroring feature works fine on my ipad mini and iphone 5s. Any advice would be helpful.