The following issue is on a 2012 iMac with Fusion Drive. I never came across this type of issue before. Also, I never owned or used a UPS battery back up before until recently. Warning, a slightly lengthy and overly detailed post ahead. I generally keep my iMac on always or in sleep mode when not in use. The few times that I needed to restart resulted in weird input device connectivity issues. I narrowed down the culprit - which I believe to be my UPS, but I wanted to begin first with describing what is going on. Currently, I use the Apple wireless keyboard, Magic Mouse and Magic Trackpad. For whatever reason whenever I restart the computer I get the following: No chime sound, a long boot time, and no input device connectivity from the bluetooth devices listed above. So I was wondering what could be going on? Problem with the Fusion Drive? So I remove the batteries from every Apple wireless device (keyboard, trackpad, mouse) and connect a generic USB mouse (that has been verified as working prior). I then hold the power button down for 10 seconds to shut it down. Remove the power cord. Wait 2 minutes or so. Plugged her back in and booted it up. Again it took a longer than usual time rebooting, and gave me no chime sound. It booted and a few start up items launched, but the mouse didn't respond. Now I decided to unplug everything from the computer. I unplugged: The ethernet connection Bose USB speakers APC UPS USB connection to my Time Machine disk I left the USB mouse plugged in. I reboot again and this time everything is working fine and there is no problem. I reboot again plugging a few more items in at a time until I narrow it down to the USB connection from the UPS. The model in question is an APC BR 700G Has anyone noticed this type of behavior on any of their Mac computers?