# Bachmann NG 2-8-0 Consolidation won't pull its shadow with DCC



## Radiodial (Mar 30, 2008)

Loco ran fine on DC, replaced the Bachmann PCB with an NCE 4amp D408SR decoder, put it on the track and it ran great! Nice crawl at 001, hauls butt at 028. Hooray! 

Then I attached an Accucraft D&RGW Passenger Coach, it won't budge - Boo!
Tried a couple of other cars, same thing. Even pushing it - can't pull it's own shadow. I can stop it with finger pressure. 

Fiddled with speed table values and CV116/117 to no avail. Tried CV 3 & 4 Acceleration & Deceleration on and off. Finally reset the decoder back via CV11, and now I have a good looking, good running loco that can't pull a single thing.

Am I missing something obvious here?

RJ Dial
NCE Pro Cab
10Amp Booster


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## Greg Elmassian (Jan 3, 2008)

Something does not sound right.... do a full reset on the decoder, but I don't think that is the problem. 

Are you perhaps starving the system for power? Read the current on the tracks (read the input current to the booster)... how much current do you draw if you short the rails? 

(I did mine yesterday, got 19.6 amps) 

Regards, Greg


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## steam5 (Jun 22, 2008)

RJ, 

Have you stripped all the Bachmann electronics? I’m not sure if this could be your problem, maybe it’s the noise suppression circuit installed on the motor causing your problems? I’m sure and someone will clear this one up… 

To test if the decoder is causing your problems, disconnect the motor from the decoder and put power to the motor, does it work okay then? 

I assume your other locomotives are working ok on DCC? 

Alan


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## Radiodial (Mar 30, 2008)

I guess I should have mentioned that there are 6 other DCC locos running on the 
layout - this was to be #7 for this weekend's open house running with a nice 
string of RGS coaches behind it. Layout works fine and is built to high 
standards. 

On DC it worked fine (pulled the coaches) before I removed the Bachmann PCB. I 
just dropped a LokSound XL in it from another loco and it works fine. Maybe it 
is another dud NCE decoder? Just doesn't make sense why it won't run with a load 
on it. I was curious as to what those two pair of resistors and capacitors are on 
top of the motor are (inaccessible), and maybe if the NCE is having fits with 
those?


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## steam5 (Jun 22, 2008)

RJ, 

Swapping the decoder is a good quick test, and it eliminated the loco in your case. 

Have you tried putting the possibly faulty decoder in a loco that you know works on DCC and with an NCE decoder? 

I can’t remember what problem the suppression circuit was causing, but next time you have yours apart remove it and directly connect the decoder to the motor. 

It is an odd problem you had. 

Alan


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## StanleyAmes (Jan 3, 2008)

The suppression circuit on top of the motor will cause strange behavior with many electronic devices. I routinely remove this circuit as part of a 2-8-0 installation.

Stan Ames


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## Radiodial (Mar 30, 2008)

That was what I was leaning to also. I can't figure out for the life of me how to get to the motor on this thing -and the exploded view Bachmann uses is of no help. 
Maybe that should have been my posting - how the heck do you get to the top of the motor on a Bachmann 2-8-0 NG Outside Frame Consolidation?? 

RJ


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## TonyWalsham (Jan 2, 2008)

RJ. 

This will show you how to get at the motor and what to fix. 

http://www.rcs-rc.com/PDF/Accessori...EN_LOC.pdf


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## DKRickman (Mar 25, 2008)

Posted By StanleyAmes on 16 Jul 2009 06:28 AM 
The suppression circuit on top of the motor will cause strange behavior with many electronic devices. I routinely remove this circuit as part of a 2-8-0 installation.

Stan Ames


Errrrm *cough*

I thought all the magic B'mann circuits were supposed to be the ultimate solution to the world's problems. Why on earth would anybody want to remove something that our benevolent overlords saw fit to install for us?


*running and ducking for cover*


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## Greg Elmassian (Jan 3, 2008)

I have a number of NCE decoders, the D808's and D408's of the same model you have. I have never bothered to remove any noise supression caps, and my Annie worked fine with a D408. 

Sounds like the decoder is cooked, send it back, they have a no-fault cost to repair. 

Regards, Greg


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## TonyWalsham (Jan 2, 2008)

Greg. 
The Annie does not have any noise suppression caps. 
The problem with the Bachmann motors that do have the suppression pcb's mounted on the end of the motor is *some* of them have the 47 mfd electrolytic caps in backwards. 
It is simpler and easier to just remove the pcb's.


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## Greg Elmassian (Jan 3, 2008)

Wow, 47 mfd, that is huge! that's not the right thing to suppress rf hash, more like a .1 to a .01 mfd cap. 

Well, I still have not removed any noise caps in my equipment for DCC, so the Aristo ones must be a bit smaller. 

Regards, Greg


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## TonyWalsham (Jan 2, 2008)

Greg, 

Take a look at the LH pic on page # 3 of those instructions I linked. 
That suppression pcb was also used on the Spectrum 2-6-0 and also caused problems. 
Those two 47 mfd caps are supposed to be wired nose to nose (or tail to tail) to make them bi-polar. Some are not wired correctly, which can put a short across the motor ouputs in one direction. 
Most pwm output ESC's do not like that much capacitance anyway. 
The later Bachmann suppression mounted on the dummy plugs on the PnP sockets, is the more common .1 mfd monoliths with small RF chokes. 

AristoCraft use a different set up.


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## Greg Elmassian (Jan 3, 2008)

Flat a** amazing.. I would guess that some of them blew up, literally. 

 Regards, Greg


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## TonyWalsham (Jan 2, 2008)

Yep. 

Assuming they were the right way round they didn't give any trouble when the loco was being controlled with regular linear DC. 
Not so with with PWM.


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## Radiodial (Mar 30, 2008)

Thanks for the instructions Tony, I will dissemble the loco and remove the board tonight and report back what happens. RJ


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## Radiodial (Mar 30, 2008)

Tony, instructions were spot on. I can't believe only 7 screws held the boiler and cab in place from the chassis. With the motor fully exposed I removed the little PC board with the two 47uf electrolytics, 2 resisters and a .01 uf ceramic cap, but alas, it made no difference. 
As a result it didn't run during the open house this last weekend. That motor sure is tiny for such a large and heavy loco. 
I have another LokSound decoder on the way after the great reviews those so equipped locos received during the open house. More to come as to whether it is the motor or the decoder.


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## Radiodial (Mar 30, 2008)

Final disposition update. I bought a LokSound XL decoder for the Bachmann, stuck it in, put a DCC-Bit Switch Smoke Relay on the Aux1 ouptou, and it runs and sounds great. I stuck the stupid NCE in a new AMS passenger coach and use it to run the lights...


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