Most likely you did not put the device into pair mode prior to entering the code. What you need to do is first power the ST3 off. With the device off, hold the green button down until you hear a language loop. When you hear the language of your choice, let go of the green button and press it once right away. You will hear a message about your phones bluetooth menu, when you hear that message go back to your phones bluetooth menu, search for devices select the ST3 and enter the pin code 0000 when prompted.
Answers & Comments
Most likely you did not put the device into pair mode prior to entering the code. What you need to do is first power the ST3 off. With the device off, hold the green button down until you hear a language loop. When you hear the language of your choice, let go of the green button and press it once right away. You will hear a message about your phones bluetooth menu, when you hear that message go back to your phones bluetooth menu, search for devices select the ST3 and enter the pin code 0000 when prompted.
Rylan