You can use the pi pwm directly to drive the npn transistor, I noticed you had only two (for kessil ?) , Pi has two PWM (18 & 19) so, you should be goodOk, I get nothing with the PCA9685, so I'm thinking it's bad. Just ordered 2 more, different brands to try them next week.
I did verify the PI PWM does work, on pin 18 I get from 0 - 3.3 volts on Channel 1. Thanks for that tip!