Rusty, thank you for the potentially helpful tips you have provided. Attached are a couple of photos showing the exposed gear train after one of my many, many attempts to get the tops of all six silver-colored "blocks" to lay flush with the supporting frame. Here, only the front-most set of drivers [the one closest to the pilot end of the loco] appear to be fully seated. The other two sets are not. This condition notwithstanding, the drivers rotate freely in both directions [albeit somewhat wobbly] when the assembly is spun by hand. The height of the individual blocks rise and fall as I do this, suggesting that the gears are not meshed correctly. Screwing the cover plate back on completely prevents wheel rotation...obviously because of the presence of one or more raised blocks.
Why won't the gear assembly fully seat?
Alas, this is embarrassing to admit, but I can't identify the "motor leads" so I can apply DC current per your recommendation. Touching various parts of the frame and wheels with wires connected to my power pack just causes sparking to occur.
Another silly question- -one borne out of ignorance: Would disconnecting the tender require later reprogramming of the decoder?
