My Bluetooth on my Mac wont pair mouse or keyboard

Are they Apple branded?

Top troubleshooting tips

1. Make sure that you have Bluetooth
   Make sure that your computer has Bluetooth built-in or that a compatible Bluetooth adapter is connected. Open System Preferences (from the Apple menu, choose System Preferences), then choose Bluetooth from the Viewmenu. If you're using a USB Bluetooth adapter, make sure that you connect it directly to a USB port on your computer—not to a port on your keyboard, display, or USB hub.
2. Check your device's system requirements
   Make sure that your computer meets your Bluetooth device's system requirements—visit the device manufacturer's website for details. This also applies to a USB Bluetooth adapter, if you use one.
3. Make sure that Bluetooth and your device are turned on
   To check your computer's Bluetooth status, choose System Preferences from the Apple menu, then click Bluetooth. In Bluetooth preferences, make sure "On" is selected (in earlier Mac OS X versions, click the Settings tab, then click the Bluetooth On button to turn on Bluetooth). Check your device to make sure that it's also powered on. If you're trying to pair a Bluetooth phone or PDA, make sure that Bluetooth is active and that the device is “discoverable” (consult your product manual if you're unsure about how to change these settings on your device).
4. Verify that you've set up your device with your computer
   If you're trying to pair a phone or handheld device with your computer, open System Preferences and click Bluetooth (and click the Devices tab in earlier Mac OS X versions). You should see your device listed. If not, follow the instructions for Syncing Bluetooth devices with your Mac above. To set up an Apple Wireless Keyboard and Mouse in earlier Mac OS X versions, open System Preferences, click Keyboard & Mouse, click the Bluetooth tab, and then click “Set Up New Device” to open the Bluetooth Setup Assistant. Follow the onscreen instructions to set up your keyboard and mouse. Some older versions of Mac OS X, include Bluetooth Setup Assistant in the Utilities folder (/Applications/Utilities) to help with pairing issues.
5. Recharge or replace your Bluetooth device's battery
   If your Bluetooth device's battery is low, you may experience connection issues. Depending on the type of device you have, try charging your battery (if your device has a rechargeable battery) or replacing disposable batteries with fresh ones.
6. Download and install the latest software for the device
   Some Bluetooth devices require you to install software before you can use them with your Mac. Make sure that you've installed any required software or that you're using the latest software available for the device on your computer. Check the device manufacturer's website for the latest updates and more information. For help with syncing a Palm OS device with your Mac over Bluetooth, see iSync 2: How to sync a Palm OS device over Bluetooth.
7. Check for a Bluetooth update
   To check for new software, choose Software Update from the Apple menu (make sure that your computer is connected to the Internet). If newer Apple Bluetooth software exists, Software Update will prompt you to install it. To install an update, select the checkbox next to the software name and then click Install.
8. Reduce potential signal interference
   Because Bluetooth works by transmitting signals through the air, some things can interfere with connections. Avoid situations in which metal objects come between your device and computer. Don't put your computer under a metal desk or in a metal cabinet. Keep your computer away from cordless phone base stations, microwave ovens, and other electrical devices that operate on a 2.4 GHz bandwidth. Make sure that your device and computer aren't more than 30 feet apart from each other.
9. Restart your computer
   Sometimes a simple restart of your Mac is all it takes to get things running smoothly again. You may also want to try resetting your computer's PRAM and NVRAM.

Everyone, my Apple bluetooth keyboard was working perfectly well with my 2012 iMac until one day it didnt work. After HOURS of trying everything including resetting PRAM and SMC (see other posts) still nothing worked. It was driving me BONKERS!

Then it dawned on me, several months ago I paired the Keyboard with my Apple TV in the lounge, several rooms down the corridor AND downstairs. A quick trip to the Apple TV showed its light was on and 'awake'. By the time I unplugged the bloody thing and got back to the iMac it had pairred!

Keyboard will only pair with one device at a time and my was pairing with the Apple TV down the corridor, NOT the iMac sitting in front of it.

Hope this helps.

BTW it had NOTHING to do with batteries, holding power buttons, installing drivers, etc, etc. It had simply paired with another device. I knew all Apple stuff works perfectly! :-)

If you are having trouble pairing your bluetooth mouse, try this: shut down the computer completely. Unplug any USB mice, then turn off the power to the bluetooth mouse. Once the computer starts back up, wait for the pop-up that is looking for a mouse. Turn on the power to the bluetooth mouse. It should work properly now.