DCC 4-4-0 Suddenly Stopped Working

[Chris K]

Hello Forum,

I have a DCC 4-4-0 which I have been running for a couple years. I use the Ez Command system and I have another Bachmann 2-6-0 DCC engine. Recently, the 4-4-0 suddenly stopped moving, but lights and sound commands still work. The 2-6-0 still works no problem, on the same layout with the same controller.

The 4-4-0 will spin the motor for a few seconds, then stop. If I "reset" the speed dial on the controller, the motor will spin for a second, then stop. Each subsequent "reset" of the dial results in the motor spinning for less and less time before stopping. It will hum/vibrate softly after it stops.

I opened up the 4-4-0 and applied DC power directly to the motor, and it spins no problem. There do not appear to be any loose wires. The engine and contacts are clean.

I'm confused as to why it would randomly stop working. 

Any help?