slipstick:
You've given the capacity of your power bank but what is its rated maximum current? Most are intended for phone charging and can supply no more than 2.4A. That is ridiculously inadequate for 12 servos, even if they are only SG90 micros.Steve
The output of the power bank is 5v - 2.4A
So would a power bank with 7A suffice?
Also I said that I tested the same set up with only 1-2 servo motors plugged in so the amperage should have been fine for that, but it still didn't do anything.