Disconnect the Gyro from the receiver,then plug in battery and center the rudder servo AND the tailrotor on shaft,via mechanical or radio operation.Once the servo centers and the tailblades go each way and center,plug the Gyro back in.
It works on mine.
When starting the Heli,after plugging the battery in,do not move the Heli for a few seconds until the light is solid on the Gyro.
What Gyro do you have.
Also the baldes may not go to neutral unless you let the stick "flick" back to neutral
I am newer to this,so others may have better advise.