Nokia Lumia 620 - My Bluetooth connection does not work

1. Make sure that your phone is not in Battery Saver or Flight mode.

2. Make sure that the pairing devices are set to be visible to one another, and that there are no obstructions blocking the space between the devices. 

3. If you cannot establish a connection or lose it soon after pairing, make sure that your phone book contacts do not have special characters or blanks before the name; rename or remove them if they do.

4. If the above steps do not help, start the pairing process from the beginning:

  1. Clear the paired devices list on your phone's Bluetooth settings and restart your phone.
  2. Reset the pairing Bluetooth device to clear information about the last Bluetooth devices.
  3. Go through the pairing process. Refer to the pairing device's user manual to find reset and pairing instructions.
  4. The Bluetooth symbol should appear on your phone screen.

Note that compatibility with 3rd Party Devices (for example, Accessories) depends on Bluetooth standards and applications related by the Device manufacturer.