I have a problem with my servo motor. I connected a servo to the PWA connection of a PCA9685, but powered the motor externally. There's no problem with that and it works fine with some smaller servo motors. But when I connect the exact same thing to the servo motors I actually want to use, the MC-410, then it doesn't work. Or, should I say, it works very spontaneously. Meaning that the servo moves only sometimes and then for a while not anymore. The problem can't be the servos, I tested them directly with the Pi and they work, just not in my setup.
The whole thing is controlled by a Rasperry Pi 3 B+, the servos are powered with 6V, 1A.
If you have any questions, please ask, I'm happy to explain further