PCA9685 issue

I´m having a problem w/ servos moving uncontrollably - I have 3 SG90 that work fine on their own, but when I attach a larger BMS620MG and give it a separate command they all move around quite at will. They all run from a 6V independent source. I also tried to switch off them using setPWM, to no avail. I use the Adafruit 9685 library.

Just to clarify for others reading this: the "A9685" above refers to the PCA9685.

show us your code

if you are having trouble setting it up go to https://www.brainy-bits.com/control-multiple-servos-with-joystick/ their website and watch the two vids and there is a link to the library at the bottom of the page.