I have a 27" iMac from late 2012. Im running OS X Yosemite 10.10.5. 3.4GHz, 16 GB Memory. Yesterday it started acting crazy. My mouse wont stay connected and now my keyboard wont stay connected. The mouse "sticks" and then scrolls like crazy and then shows not connected and reconnects again. The keyboard is now also randomly disconnecting and reconnecting and both are happening with increasing frequency. We changed the batteries in both and reset the pRam as well as running Cocktail. Its getting worse. Any suggestions or is it about to die on me?