Android 4.1 with Bluetooth keyboard
Found a possible solution from Android Central questions give it a shot.

Specifically, this post says to do the following:


  When pairing the keyboard with your device, it will prompt you to
  enter a pin and say "try 0000 or 1234." You need to:
  
  Step 1) enter "0000" on your android device (tablet or phone
  keyboard) Step 2) hit "okay" Step 3) type "0000" and hit enter
  on your BLUETOOTH keyboard