Thanks Sandro, Oracid,
It does work! the PCA9685 board did not explode, and it was able to quickly react with all the additional power. The connector is a little problematic, as with the new power source it 'chatters' probably due to poor grounding.
For testing, I using caution, making short tests, and then feeling the wires and connections for heat. Smell also works! 
I am not satisfied for long term use, for that using a better shield or making a better connection will be necessary.
