[Doug]

To isolate the problem, you may have to switch the decoder. See if it runs the same. If it does, you have an issue with the loco.

 

[Doug]

Most DCC systems use address "0" for DC locos. Not great as they buzz away with the motor being subjected to quasi AC current. If it doesn't work on address "0", then the Dynamis probably doesn't support DC. I doubt that they would have come up with a different way of doing it.