1. Make sure Bluetooth is turned on.
2. Make sure the two devices are in close enough proximity to one another. While you wouldn’t think someone might try to pair an iPad with a keyboard if the two weren’t sitting right next to each other, it’s probably worth noting that you should make sure any devices you're trying to pair are within five feet of one other.
3. Power the devices off and back on. A soft reset sometimes can resolve an issue. With computers, an easy way to do this is by going into and out of airplane mode.
4. Power down likely interferers. If a Bluetooth device was previously paired with something else, turn off that other gadget.
5. Charge up both devices you're trying to pair. Some devices have smart power management that may turn off Bluetooth if the battery level is too low. If your system isn't pairing, make sure it and the device you're trying to pair with have enough juice.
6. Delete a device from a computer and rediscover it. If your phone sees a device but isn’t receiving data from it, sometimes it helps to start from scratch. You can remove a device by tapping on its name and then Forget this Device or Unpair. After removing a device, start at step 1 on this list.
7. Get away from the Wi-Fi router. Another potential obstacle to successful pairing is interference from devices that use the same spectrum, such as your Wi-Fi router. “Wi-Fi has been designed to cope with this, but it might not be a good idea to have your devices directly on top of the router,” Powell says.
8. Move away from a USB 3.0 port. “Interference from USB 3.0 is also possible,” Powell says. Newer laptops, for example, often have the higher-speed USB 3.0 port, so if the connection isn't happening, try pairing your Bluetooth gadgets away from other computers.
9. Make sure your internet connection is not metered. If you’re having problems pairing something with your PC, you might be lacking the correct driver. The simplest way to figure this out is to check your internet server name and slide the Metered Connection to off.
10. Update the hardware’s firmware. Updates can be crucial. Forcing a web update will keep you current with any necessary changes for your system to work properly. If you are have repeated errors you may benefit from Restoring Your Database.
(Contributing site: https://www.techlicious.com/how-to/how-to-fix-bluetooth-pairing-problems/ Author: Techlicious Updated on 1/26/2017)