Bachmann 2-8-0 DCC Short Circuit

[ClintT]

Happy Holidays Folks!

I have a Digitrax DCC setup (command station, booster, throttle).  Santa delivered a Bachmann 2-8-0 DCC steam engine to my boy for Christmas.  My layout right now is a simple oval.  I've performed the "quarter test" around the layout and it passed.  I can run an analog engine using address 0.  I place the DCC steam engine on the track (by itself) and it immediately shorts the booster and it shuts down.  My throttle recognizes the engine because it shows on the throttle screen the factory programmed address of the engine, 3.

I've read in this forum and other places (though old posts) about the RF filters and in the past folks have clipped one leg of the capacitor to eliminate this problem.  The paperwork with the engine indicates that these filters shouldn't be an issue.  For grins I removed the tender cover to look at the circuit board.  It looks quite a bit different than the pictures I've seen online.

The paperwork with the engine does mention that there are RF chokes (in the form of capacitors and inductors) on the circuit board and that they can be removed.  Though it should only need to be removed for non-NMRA standard decoders.

At this point I have no idea what I should do next.  Is there more troubleshooting I can perform?  Are folks still experiencing this sort of problem similar to what was happening a few years ago?  Any help would be appreciated.

Cheers!
ClintT

[ClintT]

Hunt,

Thanks, I do remember people mentioning this type of situation in the past.  I checked the trucks.  The front truck has the insulated wheels on the opposite side of the insulated wheels on the back truck, just like the drawing.  Does it matter which side the insulated wheels are on for each truck?  I speculate that what matters is only that they are opposite.

Any other ideas?

Thanks,
ClintT

[Jim Banner]

It does matter which side the insulated wheels are on.  If both trucks are reversed, they will both be wrong way round compared to the locomotive wheels.  A quick and easy test is to put the 2-8-0 on the rails and hold the tender just off the rails behind it, or put a sheet of paper between the tender wheels (just the tender wheels!) and the track.  If the short circuit disappears, the problem is in the tender and mostly likely in the tender wheels.  If the short circuit is still present, the problem is most likely in the locomotive.

If the above test shows a problem in the locomotive, you might want to do another test.  Carefully unplug the tender and set just the locomotive on the track.  If the short is still present, the problem is in the locomotive wheels or wiring to the tender plug.  If the short is gone, the the problem is between the tender plug and the decoder, or in the decoder itself.

About those pesky capacitors - they interfere only with silent decoders that pulse the motors at rates higher than the human ear can hear.  And only with silent decoders do you have to disconnect them (cut one lead, chop them out, etc.) and then only if they interfere with decoder operation.  Bachmann decoders pulse the motors at a lower frequency and are not therefor bothered by the capacitors.

Rereading your initial post, it sounds like you are using a Digitrax Super Chief or Super Empire Builder set.  If that is the case, I assume you heard the clicking at about once per second when you did the quarter test and you hear that same clicking when the locomotive shorts the track now.  Otherwise I would be reminding you that just because your throttle (either a DT400 or DT402) shows address 03 does not guarantee that 03 is the address of the locomotive.  I would expect it to be 03 when received but the 03 showing in your throttle is a result of entering 03 when you tried to pick up that address.  Or am I missing something here?

Jim