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Stop and Go Locomotive

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  • Member since
    January 2003
  • From: Ridgeville,South Carolina
  • 1,294 posts
Stop and Go Locomotive
Posted by willy6 on Monday, May 31, 2021 8:09 AM

I have a fairly new Athearn HO dcc/sound RTR locomotive. I did a few adjustments using JMRI, mainly volumes and it ran fine. The other day I went to run it and it was stop and go about every 5 feet. The track is ok. I ran 4 other locomotives (Athearn and one Intermountain) without problems. I cleaned the wheels to no avail. Any ideas or info would be greatly appreciated.

Being old is when you didn't loose it, it's that you just can't remember where you put it.
  • Member since
    March 2010
  • From: Sherwood Park, Alberta, Canada
  • 252 posts
Posted by CNR378 on Monday, May 31, 2021 8:21 AM

What DCC system are you using?

Assuming Digitrax, you possibly have the locomotive acquired on more than one throttle.

Peter

  • Member since
    February 2015
  • From: Ludington, MI
  • 1,862 posts
Posted by Water Level Route on Monday, May 31, 2021 8:36 AM

I had the same problem with a dcc/sound Athearn F3.  Ran fine when I first got it.  began the stop and go pattern on its own.  Sometimes would run 10 feet before stopping, sometimes 2 inches.  No amount of resetting the decoder helped, nor did adjusting any CVs.  Since it also sounded fairly atrocious compared to my other sound locos, I ditched the decoder and it solved it.  Good luck.

Mike

  • Member since
    September 2014
  • From: 10,430’ (3,179 m)
  • 2,311 posts
Posted by jjdamnit on Monday, May 31, 2021 12:39 PM

Hello All,

Which locomotive model?

New or used?

Do you know the manufacturer and decoder number i.e. SoundTraxx Tsunami2

What CVs did you manipulate?

Have you tried resetting the decoder per the manufacturer's recommendations?

Answering these questions will help the great folks on these forums assist you.

Hope this helps.  

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,483 posts
Posted by MisterBeasley on Monday, May 31, 2021 1:08 PM

I would suspect either dirty wheels on the locomotive or a loose wire.  When it stalls, do the sounds stay on?  How about the lights?

It takes an iron man to play with a toy iron horse. 

  • Member since
    February 2015
  • From: Ludington, MI
  • 1,862 posts
Posted by Water Level Route on Tuesday, June 1, 2021 5:44 AM

We'll see if Willy6 responds, but at least in my experience it wasn't your obvious dirty wheel or bad wheel wiper issue.  The loco would actually slow down and accelerate on it's own with no interruption in power to the unit.  It was pretty clear something went haywire in the decoder.

Mike

  • Member since
    January 2003
  • From: Ridgeville,South Carolina
  • 1,294 posts
Posted by willy6 on Saturday, June 5, 2021 9:58 AM

Digitrax using one thottle and the only loco on the track. When it stops, no lights or sound. The stop is about 1 second each time. Only adjustments made were through JMRI and they were volume adjustments and programmed road number. It always ran fine and was never dropped. It started doing this when it was MUed with 4 other locomotives. It was the 3rd in line. I removed it from the MU group, removed the other locomotives and ran this alone to see it stopping at will.

Being old is when you didn't loose it, it's that you just can't remember where you put it.
  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Saturday, June 5, 2021 11:22 AM

What happened when you did the factory reset (e.g. set CV8 to 8)?  

Here is a Digitrax page for resetting decoders:

https://www.digitrax.com/tsd/cvs-mobile-decoder-configuration-variables/reset-moblile-decoder-to-factory-settings-cv08/

Since he knows how to use JMRI he should have no trouble reconfiguring the decoder 'step by step' to see if a change in settings reproduces weird behavior.  He should also have no trouble finding out what the manufacturer value preset in CV8 is, which will tell him fairly definitively what kind of decoder is installed.

Is the engine still under Athearn warranty of any kind, or has he contacted them for technical advice directly?

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,483 posts
Posted by MisterBeasley on Saturday, June 5, 2021 2:23 PM

I still suspect a loose wire, particularly a power wire from the wheels to the decoder.

Does the locomotive pick particular places to stop, like curves or turnouts?  That again says loose wire to me.

It sounds like you have not removed the shell to actually look inside.  Can you do that?  Can any members here describe how to remove the shell on this engine?  My Athearn engines are all at least 50 years old, so I can't be of much help there.

It takes an iron man to play with a toy iron horse. 

  • Member since
    January 2003
  • From: Ridgeville,South Carolina
  • 1,294 posts
Posted by willy6 on Sunday, June 6, 2021 8:26 AM

I will remove the shell and see whats going on. Thanks for the advice.

Being old is when you didn't loose it, it's that you just can't remember where you put it.
  • Member since
    May 2004
  • 7,500 posts
Posted by 7j43k on Sunday, June 6, 2021 11:22 AM

On the loose wire theme:

 

I bought an ABBA set of sound equipped Athearn UP GP9's.  It seemed like most of the headlights were out, but they ran fine and the sound worked.

Assuming that surely the bulbs/LEDs couldn't ALL have been bad, I soldered all the wires to the PC board, after removing the push-on clips.

All the lights then worked.

That was, so far, the only time I've run into this problem--every other loco I've got has lights that work just fine from the factory.

But not these.

 

Ed

  • Member since
    November 2013
  • 2,775 posts
Posted by snjroy on Tuesday, June 8, 2021 9:13 AM

CNR378

What DCC system are you using?

Assuming Digitrax, you possibly have the locomotive acquired on more than one throttle.

Peter

 

I did not see a response to Peter's suggestion. I get the same problem regularly with my Zephyr system and it is easily fixed by clearing all stored addresses. It's in the manual. I have many locos Sad and I need to clear the system on a fairly regular basis. A reset of the decoder could also help, but if I were you, I would look for the list of default CVs for that loco before doing that.

Simon   

  • Member since
    February 2002
  • From: Mpls/St.Paul
  • 13,892 posts
Posted by wjstix on Wednesday, June 9, 2021 1:24 PM

willy6
It started doing this when it was MUed with 4 other locomotives. It was the 3rd in line. I removed it from the MU group, removed the other locomotives and ran this alone to see it stopping at will.

If possible, try running it on DC and see what happens. If it runs on DC with no problems, it's not a mechanical issue (loose wire etc.); it's something with the decoder.

Given your description of what happens, I'm very suspicious that it's somehow still connected to the consist address. Maybe punch in the address of the lead engine with just this engine on the track, and see if it responds.

Each DCC system is a little different re consists, but maybe you can go into your system and delete all the consists?

Stix
  • Member since
    July 2009
  • From: lavale, md
  • 4,678 posts
Posted by gregc on Wednesday, June 9, 2021 2:04 PM

Overmod
What happened when you did the factory reset (e.g. set CV8 to 8)?  

i had a decoder that wouldn't run.   but when placed on the track the wheels would turn a ~revolution and stop.   made no sense.

worked fine after a reset

greg - Philadelphia & Reading / Reading

  • Member since
    February 2002
  • From: Mpls/St.Paul
  • 13,892 posts
Posted by wjstix on Thursday, June 10, 2021 10:38 AM

In general I like to start with the least "invasive" possible solution first, like a re-set or something, rather than going right to opening up the engine and digging around inside.

If a re-set isn't doing it, my guess is still that the engine is still a 'trailing' engine in a consist in the OP's DCC system. I've done that on my layout, and the way the engine runs is just like what the OP is describing.

Stix

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