I have a few tricopters, all Naze32, and I have not understood the logic driving the buzzer, especially when transmitter signal is lost. On some set-ups the default is that buzzer starts bleating a few seconds after loss of signal, which would serve as a lost model alarm. However, in some other cases it would not. The buzzer otherwise works, making all the right noises when arming, disarming and switching flight modes. I noticed that, when you connect the flight battery without the transmitter being on, it will bleat. Once the radio comes on line, it stops. But when I switch off the radio, it stays silent. Would appreciate help. BTW, the buzzer responds as expected when assigning it to a switch.