Yesterday we had the power switched off and my computer was not shutdown cleanly. When it was powered back up my iMac flashed up there was no keyboard attached. It seemed to of lost the connection.
I tried the first obvious things, try switching the keyboard off and on again, still nothing, it would say connecting to my keyboard, but then it would say connection failed.
Next I tried to shutdown the computer again, switch off the trackpad and keyboard, switch them back on then the computer, again same as before it would say attempting but would not connect. I plugged in a Microsoft keyboard, so I could login and try the next steps.
Once the computer had loaded, I opened bluetooth preferences to watch it connect. At this point I thought I would try new batteries, although I know it hasn't warned me the batteries are low, but try all the trouble shooting steps.
I deleted the Bluetooth plist file incase this was corrupted, I didn't think it was as my trackpad was still working, but it was worth a try, so I deleted it and rebooted, same again. Then I restored an old file from Thursday again same results.
I tried making to ensure the keyboard was Discoverable, you do this by pressing and holding the ON button, the keyboard comes on, then continue holding the button until it starts to flash. This is when it got strange. The lights would flash twice then the light would stay on just for a couple of seconds as if it was connected, although the computer would still be saying not able to connect. It was all getting very frustrating, so I was about to take a break and check Clash of Clans on the ipad, when I remembered this keyboard used to be the one I used with my ipad, I had to switch this to my iMac after my kids spilt a drink of coke over my original keyboard.
I placed my iPad into Airplane mode, switched the keyboard off, switched it back on and bazinga, it would say it's connected. It then gave me a code to enter in to pair the keyboard to the computer. As soon as I entered the code they were paired. I then took my iPad out of Airplane mode and everthing has been fine since.
Very strange indeed, but just incase anyone is about to smash the keyboard as it won't connect, this is something to try if you have had this connected to another device previously.
I am always interested in your thoughts so if you have any comments or feedback then please feel free to add any comments, or you can mail me here.