I have recently finished assembling my F-16 turbine jet, and installed brand new, out of the box JR 8611a servos. Both servos are mounted with no binding and move freely throughout servo travel. Servos have been tested in workshop during installation/setting and showed no sign of failure or unusual buzzing sounds….
On maiden day, luckily, I was doing usual range check and suddenly right elevator started wobbling up and down a few millimeters even when stick is moved, as if servo was not able to hold center position, furthermore, servo started buzzing abnormally.
I consider myself extremely lucky not to have had this defect during flight as this would surely have meant disaster with possibly no mean of knowing real cause…

Furthermore, back to workshop when I tried to operate servo, at the beginning, it worked without problems, after a few minutes (leaving power on) servo started to glitch again giving same weird noise.
Just to make sure that I had no problem with my wiring or RX, I plugged the servo directly to a new RX and had same failure.
Changed servo to a new one and problem was solved.

I am about to send defective 8611a for repair.
Regards,