How to stop Bluetooth setup assistant
If your mac is already booting then,
- Open System Preferences.
- Click Bluetooth.
- Click Advanced…
- Uncheck Open Bluetooth Setup Assistant at startup if no keyboard is detected.
- Uncheck Open Bluetooth Setup Assistant at startup if no mouse or trackpad is detected.
- Click Ok
If on the startup then nothing would work.
No safe mode nor pressing shift key or any other thing.
The only thing you could try which worked for me was to open the back lid and see if any screw is loose,do this at your own risk or else getting it serviced is the only option left if you are under warranty