Defective Bachman DCC On Board?

Model Railroader Electronics and DCC
1

Hello,

I recently picked up a Bachman GP38-2 locomotive (BNSF 2344, Item #61118) labeled “DCC On Board” at a good discount from a hobby shop in another city while on a road trip last week (mistake #1). For whatever reason they did not test it on their bench before I left (mistake #2). Upon setting it out on my Digitrax based layout after returning home I cranked everything up, set my DT400 throttle to address 03 and began to apply a few notches of power. Not good. The motor emitted an extraordiarily loud humming noise like 60 cycle AC applied to a transformer with loose windings. Applying some more throttle only exaserbated the problem but the loco did move on out humming louder at each throttle increase. Ditto in reverse. Lights okay. Removing the shell reduced the volume somewhat (resonance I suspect) but I could feel the serious vibration by touching the motor. The loco did not respond to address 00 so there must be DCC a decoder buried somewhere on the circuit board.

Anyone with experience in a matter such as this? Monday I can a) return for a refund, or b) return for an exchange, or c) return to Bachman for warranty repair. And, of course there is always the opportunity for the dealer or Bachman to say “it works fine for us”. Guidance would be appreciated. Thanks, Geoff

2

Bachmann is pretty good about standing behind their product. You might first send them an e-mail and maybe they’ll have some simple suggestions.

Have you tried programming and/or reading-back CVs? That will tell you something about how functional the decoder is.

If you have an LHS you deal with regularly, bring it there and see if the engine will work on their system.

3

Sounds like this is a mechanical issue. Check the drive shafts. Maybe a cracked gear, front or rear truck.

The on board non sound is a low end Lenz decoder.

The Bachmann site has the EZ Command DCC list for the decoder.

These on board for the Diesel’s are poor enough that a few years ago, NCE developed the non sound Bach-DSL decoder.

Google bach-dsl.

Rich

4

I’ve only had three Bachmann engines with that decoder and they all exhibited the same thing. They are a cheap decoder that function at a lower frequency than most decoders.

I replaced the decoders with some from TCS and the difference was night and day. Engines I was on the verge of dumping are now some great runners.

Mark.

5

Thanks Mark, that was my suspicion. My usual wisdom is not to buy DCC locomotives with an unknown / manufacturer decoder (mistake #3). Indeed, the sound was not the usual high frequency resonance I’ve become used to if something is not quite right with the decoder / motor combination or running a DC loco on a DCC layout at address 00. Other than that initially seemed to be a smooth runner. I’ll see what the dealer works out and go from there. I’m all Digitrax with only a couple of TCS decoders and with spares I could modify the lighting board and drop one in if need be and move ahead. Lesson learned. Thanks again, Geoff

6

I am with Mark. I bought a “DCC ON BOARD” Bachmann GP9 a few years ago. It also emitted a loud humming sound and the control of low speed was awful. This was a very basic decoder. I changed it for a new one from TCS. Good running and silent loco now.

7

Same here guys…I just replaced a bachmann decoder with the upgraded factory replacement from NCE. What a difference!! No more humming noises or crapping out all over the layout. Now it’s a main line terror instead of sitting on a siding looking all stupid…

Rich