Now that I have seen the video, the issue seems to be more of a skipped chuff trigger than anything. The markers on the tender do not even flicker when the skip occurs so that rules out an electric issue (what I was referring to with my mechanical comment). The soundboard in the tender should already have the "chuff on" firmware update embedded in the code (it fixes the issue earlier locos had where the power would drop out and the sounds would shut off, requiring an AUX1 0 reset to bring them back to life. I believe that is aleady there, so a firmware update is off the table)
I agree with GRJ, you are having a momentary drawbar alignment issue where the IR Receiver is not seeing that chuff command. There is no mechanical switch in the loco to chase after, all the chuff triggers are generated by the RCMC/Flywheel encoder, sent through the IR Transmitter to the tender,and then played in the tender/speaker.
Good news is, there is no mechanical / electrical issue. Bad news is, you're gonna chase your tail on this for a while, trying to figure out what the "perfect combination" of drawbar alignment needs to be!
Good luck, let me know if I can be of any assistance in your "discovery process". Gotta love toy trains!
Thanks,
Mike
