First, make sure the battery is fully engaged and no gaps show towards the back. So the drone lights up but does not go thru the camera gimbal initiation routine? Do you not hear the fan start up? When you connect the controller with the smartphone do you get a Not Connected message in red at the top of the fly screen?
Also, if you press the on/off button slightly too long all you get is battery status....at least for the Anafi, I think the Bebop is similar in that regard.