Locked out of my Mac? Recently when I was on my Mac I had turned off Bluetooth accidentally when I had meant to turn the WiFi off and back on (the WiFi was acting up). I logged off when I had to get off. And since my Mac keyboard is the default Bluetooth connected one that you get when you purchase it, it decided to not work. 

When I came back later to finish up some things, I turned on my keyboard and typed my password, but nothing showed up in the box. The keyboard, when I turned it on, the light flashed until I finished typing, the  turned off. It didn't type anything into the password box, despite being on. 

I replaced the batteries thinking it was dead, but that didn't work either. I have no USB connected keyboard to access my mac, I can't access Bluetooth, and my keyboard wont do jack squat. 

I don't know how to log in! 

How can I log in when Bluetooth is turned off?

(Also if my explanation doesn't make much sense, I have a video instead. )
You can reconnect your Bluetooth keyboard/mouse by cold starting/rebooting your Mac with the physical power button.


Make sure you keyboard is turned on
Disconnect all physical devices from the Mac, including any peripherals (printers, scanners, USB flash, etc)
Reboot the Mac (or boot the Mac if it was shut down) using the physical hardware button located on the machine 


This will trigger the Bluetooth setup wizard and detect the Bluetooth devices and enable the service automatically.

Taken from OSXDaily.com - How to Enable Bluetooth Without a Keyboard or Mouse on Mac