Anybody ever experienced servo arm move by itself without any control input from Tx

[LarryLim]

Has anybody ever experienced servo arm move by itself without any control input from Tx? The right cyclic servo arm(Powertech digital servo, torque 2.7 kg) of my Mini Titan keep on moving up and down by itself whenever i fix up the batt. I had ever tested it with servo tester but nothing wrong with it. I'm using a Spektrum Tx 7 and AR7000 receiver, Castle Creation 80A ESC, Gyro 240 and Rudder Airtenic servo torque 1.6. Pls advice.

[Adrianli]

That means ur servo up lorry already, it cant find the center by itself so keep moving up n down.

The last time I had tis problem was wif my HS55 on the first Trex450 on my Alierons. The heli would move left n right on its own while hovering stationary!!! It was fun to watch but dangerous to fly as u wouldnt know when it'll stop moving n the heli goes out of control.

[nacar]

Has anybody ever experienced servo arm move by itself without any control input from Tx? The right cyclic servo arm(Powertech digital servo, torque 2.7 kg) of my Mini Titan keep on moving up and down by itself whenever i fix up the batt. I had ever tested it with servo tester but nothing wrong with it. I'm using a Spektrum Tx 7 and AR7000 receiver, Castle Creation 80A ESC, Gyro 240 and Rudder Airtenic servo torque 1.6. Pls advice.

Switch the twitching servo with another good servo on the RX (eg. swap the left cyclic servo with the right cyclic servo) and see if the twitching still happens with the same servo. If same servo still twitching, then the problem is with the servo. If the twitching now happens to the supposedly good servo, then the problem lies somewhere else (eg. rx, tx, ...etc)