I put my scale Polar Express (6-11451) on the layout and applied 18v last night. The tender started buzzing loudly like speaker feedback, but then the coupler released some magic smoke... Did the sound board fail or the coupler? Or both?
This tender has been a bit flaky since day 1. Even though both rollers are clean, and undamaged, I always had to run a 9v battery in the tender to keep the sound from dropping out. Of course I always remove it at the end of the season for storage...