It's easy for you to turn on Bluetooth on your MacBook. You can go to System Settings > Bluetooth or Control Center in the menu bar. But sometimes, the MacBook Bluetooth goes wrong.
This issue can be affected by the system, the settings, or other devices connected to Mac. Following the below methods to try to fix the MacBook Bluetooth won't turn on.
Method 1: Turn the Bluetooth off and then on. Sometimes, it seems like the Bluetooth is turning on but actually off. At this time, just re-enabling your MacBook Bluetooth can fix the temporary error.
Method 2: Restart your MacBook. Restarting your MacBook can refresh the macOS and built-in apps to the new state. It helps you to fix most of the minor issues on your MacBook.
Method 3: Disconnect all external devices. The external devices can be the reason that causes your Bluetooth won't turn on. Thus, unplug unnecessary devices and try to turn on your Bluetooth to check if it can work this time.
Method 4: Resetting the Bluetooth module.
After the process is finished, exit Terminal and then restart your MacBook to check whether your Bluetooth is running well.
Method 5: Update your MacBook Bluetooth. Outdated Bluetooth can also cause this issue. So go to System Settings > General > Software Update to check whether there is a new version of macOS. If there is a new macOS, click Install Now to update.