@terryd73 posted:I don’t know if this will help but I had the same issue with my B&O F7 ABA set and even ended up sending it to GGG who tested the board and sent it back saying nothing was wrong with it. He did suggest a friction issue so I pulled both motors in both units and lightly greased the gears and carefully reassembled and the problem went away. George said that it was most likely that one of the motors was slightly misaligned, maybe your issue could be something that simple as well.
Correct, again, the limitation of the system is only 1 motor is sensed for RPM feedback. The assumption is, all the other trucks and motors are free, not binding, and thus the same voltage (PWM) makes them spin with the same RPM as the sensed motor. That's only valid as long as none of them are fighting friction and losses within the truck and gearing.
