Yea; I tested it multiple ways on other channels and receivers.

It's the servo.

We've had several Hitecs die locally, all from current production "new" digitals.

2- 7940's. 1- would center but randomly actuate. the other is mine, as described above.

Then a 4-hour old 7955 that did the same as the later 7940, where it would center, but only actuate for a short time then re-center and stop until torque was manually applied to the arm, then it would kick a couple times. Hitec sent a note back saying it was a motor failure in the servo.

I'm just glad mine didn't fail on the track and cause a runaway.