Model Railroading > Decoder Installation Issue/ Question - Latest Atlas HO GP40-2-(W)

I will open by saying this unit does NOT have any documentation in the box with it...it is from the laterst run of GP40-2 (W)  models that just now arrived. 
I also looked on the Atlas web sirte in their documentation link about this and there is nothing in there about this unit or adding a decoder to any Silver Series unit for that matter....so let me describe what is going on. 

Removing the hood section over the decoder location, we find an 8-pin plug and a 21 pin plug.  The Atlas Web Site says of this model: ( including all models of THIS run) Atlas Master™ Series Silver Additional Features:

• NMRA 8-pin plug for DCC (Decoder-ready)

So to me it is reasonable to expect that the 8 pin decoder socket should be used? So I bought some TCS-DP5 decoders which are very small and very thinn....and fit inside the Atlas carbody in the 8 pin plug they have there.  So I ignored the 21 pin plug and plugged the decoder into the 8 pin plug...put it on the Program Track, and it began to run at a good clip and nearly ran off the prograaming track....

So I decdied that maybe the 21 pin plug unit needed to be removed, as it does in some other mfgr units - so I did that....it easily unplugs and so I assumed that was a necessary step....replaced the 8 pin decoder and put it on the programming track...no run away - took programming.....put it on track....runs beautifully - but....no headlights. No ditch lights.   Hmmm...looked at the21 pin board I removed....looks like the resistors for the lights were there.....so I replace the 21 pin board...replace the 8 pin decoder....tried turning it 180 degrees....still runs away on programming track.  My next step is to remove the 21 pin - reprogram the unit so it runs again - THEN replace the 21 pin board and see if I get lights....Maybe only my box had no prograaming instruction included - if anyone else did get one for this 8 pin and 21- pin setup  -perhaps ypou can share what it says?

Will try this tonight and let you know what happened. 

Bob

 



Edited 1 time(s). Last edit at 08/11/19 09:08 by navarch2.

Do not put the 21 pin board back in.  It is a jumper board for running on DC.  What happens when you put it in along with the 8-pin decoder us that it connects the track voltage directly to the motor, which is why it runs away.  The correct orientation for the 8-pin plug is for the orange wire to be at position 1 on the socket.  This is usually denoted by a * on the circuit board.  If the headlights and ditch lights still don't work, it could be that you damaged to decoder by running the engine with the jumper plug installed, or you damaged the lights by having the jumper installed along with the 8-pin decoder.

If the lights still don't work after turning the 8-pin plug around try this. Remove the decoder, install the jumper, and run the engine on DC and see if the lights work.  If they do, then the problem is in the decoder.  If that is the case, then go purchase a 21 pin decoder and use that.  If you have onther engine that uses the 8-pin decoder, put this decoder in that engine and see if the lights work.

Good luck,

Stuart

Thank you Stuart;

The lights are dead, and given that Atlas did not put any direction into the box, and had nothing posted in their "Manaul" section of the site,  it unfortunately, goes back to the LHS Tuesday, as a bad board issue - runs but no lights and a missing instruction sheet.
This is the first time I have encountered that 21 pin/8 pin configuration. The unit is advertised with an 8-pin decoder socket, so the instruction sheet was key.  Atlas should have been more careful about providing proper instruction in each box. 

Life goes on :)

Bob




Gulliver-Stuart Wrote:
-------------------------------------------------------
> Do not put the 21 pin board back in.  It is a
> jumper board for running on DC.  What happens
> when you put it in along with the 8-pin decoder us
> that it connects the track voltage directly to the
> motor, which is why it runs away.  The correct
> orientation for the 8-pin plug is for the orange
> wire to be at position 1 on the socket.  This is
> usually denoted by a * on the circuit board.  If
> the headlights and ditch lights still don't work,
> it could be that you damaged to decoder by running
> the engine with the jumper plug installed, or you
> damaged the lights by having the jumper installed
> along with the 8-pin decoder.
>
> If the lights still don't work after turning the
> 8-pin plug around try this. Remove the decoder,
> install the jumper, and run the engine on DC and
> see if the lights work.  If they do, then the
> problem is in the decoder.  If that is the case,
> then go purchase a 21 pin decoder and use that. 
> If you have onther engine that uses the 8-pin
> decoder, put this decoder in that engine and see
> if the lights work.
>
> Good luck,
>
> Stuart

Bob,

Sorry to hear that the lights are dead.  Good luck getting the engine repaired/replaced.

These "combination boards" (8-pin/21-pin like Altas, or the older 8-pin/9-pin like Athearn) can be a real pain for those new to DCC.  As you stated, proper and correct documentation by the importers is a must.  I've seen blown decoders in Athearn engines where the modeler installed an 8-pin decoder without removing the 9-pin jumper. A warning sticker on the jumper stating "remove before installing a DCC decoder" would be a big help.

Stuart

Hello Stuart;

The TCS DP5 decoder was made "specifically to fit in Atlas Silver Series HO Scale locomotives" . The literature with the decoder does not anticipate the need to deal with a 21 pin board, and the unit is not covered on the TCS web site. I checked both of them - yet the packaging clearly stares in is for the Atlas Silver Series units.  I have used it on MP15's successfully, and in many older Atlas units and Kato units as well.  I do have Pin 1 in the right place as it is now. It is increasingly obvious that the 21 pin board should have been removed at the outset - but it wass not obvious that it was removeable, nor stated that it had to be. Had even  the normal Atlas parts diagram been included with the model, that board would have been identified as a jumper board and I'd have removed it.  The decoder itself was not damaged - it worked when I put it into an old Kato unit to test it. 

I am going to look into your suggestions regarding shutting down the auto-start on the Tsunami decoders.  Thank you for your help.


Gulliver-Stuart Wrote:
-------------------------------------------------------
> Do not put the 21 pin board back in.  It is a
> jumper board for running on DC.  What happens
> when you put it in along with the 8-pin decoder us
> that it connects the track voltage directly to the
> motor, which is why it runs away.  The correct
> orientation for the 8-pin plug is for the orange
> wire to be at position 1 on the socket.  This is
> usually denoted by a * on the circuit board.  If
> the headlights and ditch lights still don't work,
> it could be that you damaged to decoder by running
> the engine with the jumper plug installed, or you
> damaged the lights by having the jumper installed
> along with the 8-pin decoder.
>
> If the lights still don't work after turning the
> 8-pin plug around try this. Remove the decoder,
> install the jumper, and run the engine on DC and
> see if the lights work.  If they do, then the
> problem is in the decoder.  If that is the case,
> then go purchase a 21 pin decoder and use that. 
> If you have onther engine that uses the 8-pin
> decoder, put this decoder in that engine and see
> if the lights work.
>
> Good luck,
>
> Stuart

I am anything BUT new to DCC....but I am not an electronics expert by any definition... I do have literally hundreds of successful DCC decoder installs to my record.....but to me that installation looked like the female plug was simply a 21 pin alternate decoder install plug. That is much like the Athearn 9 pin/8 pin setup.  There, you remove the jumper and I have done many of those - but the need is pointed out in the instruction sheet.  This 21 pin female plug does not look like that. It looks like part of the board itself.  Even I eventually figured it out.   

My LHS will take the unit back - that will not be an issue, he stands behind things he sells...no problem there.

Bob

Gulliver-Stuart Wrote:
-------------------------------------------------------
> Bob,
>
> Sorry to hear that the lights are dead.  Good
> luck getting the engine repaired/replaced.
>
> These "combination boards" (8-pin/21-pin like
> Altas, or the older 8-pin/9-pin like Athearn) can
> be a real pain for those new to DCC.  As you
> stated, proper and correct documentation by the
> importers is a must.  I've seen blown decoders in
> Athearn engines where the modeler installed an
> 8-pin decoder without removing the 9-pin jumper. A
> warning sticker on the jumper stating "remove
> before installing a DCC decoder" would be a big
> help.
>
> Stuart