I just had 2 brand new Y6 builds hit the ground the exact same way. Both boards flew great in X4 config a month ago but now both hit the ground in 60 seconds after ARM.
I went thru all 3 logs but for the life of me, I cannot ID any root cause.
Copter_1-flight_1: started acting strange at mode change from STAB to ALThold, copter starts acting strange and crashes gently.
Copter_1-flight_2: takeoff in ALThold flies nice for 30 sec then starts twitching right looses orientation and crashes hard.
Copter_2- flight_1 (all components are different, even the batteries): 30 seconds after takeoff starts twitching to the left then complete loss of orientation and it hits the ground upside down.