"Pins 13 and 14 on the 74ACT157 show PWM, but pin 12 (the output) shows nothing. I'm pretty sure I busted the multiplexer. I guess I'll try my hand at replacing it before spending the $60 on a new board."
I setup ArduCopter today, and everything was fine. I was playing with calibration, and at some poin output 4 stopped working. I hooked up my scope, and I see the PWM signals on outputs 1, 2, and 3 - but nothing on 4. I traced back to the…