Over the past few weeks I have had problems with my Keyboard and Mouse. It started a couple of weeks back when i upgrade to El Capitan. When the computer goes into sleep mode for a couple of hours the unit will loose connectivity with the keyboard. this makes it rather harder to enter your password when you wake the machine up. I have wiped and reloaded the iMac 5k a few times with El Cap and it now seems to be acting a bit better with sleep mode, but has now decided to randomly drop connection with the mouse while turned on, as well the keyboard sporadically stops responding and then decided to enter the last key pressed for a second or two.. not fun when you are trying in a forum, or pressed the delete key just before it acts up. I have contacted Apple as I have AppleCare on the unit, and they have recommend that I take the unit into the AppleStore to get the genius to look at it and see if there is a fault with the bluetooth antena inside. Q? How long does it take for Apple to fix these machines? I use my computer all the time and don't want to loose it for months on end. It's the only way to backup my iPad and I use it for media work among other things. The people at AppleCare said it depends on their work load and if they have parts. My appointment is for a week from now. Wouldn't apple if they are taking a computer in to fix a part inside, pre-order the part so you are not waiting for them. What I don't understand however is that I have an apple trackpad that works fine all the time and never has a problem or disconnects or does anything wrong. Wonder if the keyboard was the first thing that went and I don't know enough about bluetooth to know if one device going wrong could kill or cause problems with other devices attached to the same computer?? I do have a usb apple keyboard that I could steel from my other mac mini to see if the problem with the mouse continues if the wireless keyboard is removed from the picture.. What do you think?