DCC locomotive lights respond but locomotive won’t move

[El Robbie]

Setup: small oval of HO EZ Track, Bachmann EZ Controller DCC and powerpack. Everything was running fine. Then today the DCC locomotives will respond to function commands (lights come on, sound works), but they won't move.

Problem persists with two different locomotives: a Bachmann Alco RS-3 diesel (DCC on Board) and a Bachmann Baldwin 4-6-0 steam locomotive (Sound Value on Board).

Makes no sense to me why sound and lights work but neither loco will run. Signals are clearly getting through to the locomotives. Discussions of similar "lights work, loco won't run" problems on other forums have pointed to a loose connection within a loco between the pickups and the motor, but the odds of connections suddenly becoming loose on two different locos simultaneously are astronomical.

So I'm looking at the EZ Controller and/or powerpack as likely culprits. I've checked wiring connections to the track and checked integrity of connections between track sections. I've unplugged everything and let it sit for several hours, hoping a breaker will reset, but no change.

Any help will be appreciated.

[Flare]

Sounds to me like the controller's knob stopped working.

[Trainman203]

See if the engines work on another layout.

[El Robbie]

Don't have another layout to try them on ... but I hooked up a Bachmann DC controller to the same track in place of the DCC controller, and the engines DO run in DC mode.

[Trainman203]

If both the DCC and the DC engine move with another power source, that seems to identify the original power source as the issue.

I have wireless NCE power pro DCC on my layout, which i bought to replace the original EZ command I started with that served quite well for a couple of years until I wanted to greatly expand operations.   I found out, even in the EZ command days, that it was very good to have a backup system to be able to continue operation while something or another that failed was being repaired or replaced.  With the NCE , it got costly but was worth it to me to not have to wait for 6 or 8 weeks or more for something to return repaired.

[El Robbie]

Trainman, I may not have been clear. I didn't hook up a different power source, I hooked up a different controller—DC vs DCC—with the same powerpack. To me, that suggests the DCC controller is the problem.

Flare, at first I was skeptical of your suggestion that the controller knob stopped working. But I was limiting my thinking to a mechanical failure of the knob, and I realized after awhile that the section of the CPU that receives and processes signals from the knob may have gotten zapped. So you were probably on to something.

Anyway, it's still under warranty, so I'm sending back both the DCC controller and the powerpack. I'll let Bachmann figure out which is defective.

Thanks to all for the input.