DCC engine sensitive to shorts

Discussion in 'DCC & Electronics' started by eric halpin, Mar 18, 2008.

  1. eric halpin

    eric halpin Eric Halpin


    I have a Proto 2000 GP7 with sound on board. Sometimes, when a good short occurs on the layout this GP7 starts going nuts. That is, even when it is NOT being used and sitting idle on a spur track, the short on the layout causes this loco to start up, bells and horns commence tooting, etc. It is very sensitive to a short unlike all its other brothers on the layout! What cv can I access to tone down or reduce its sensitivity to these conditions? To quite the loco, all I do is lift one side of the loco from the tracks and it goes back to sleep (after clearing the short).

  2. steamhead

    steamhead Active Member

    What system are you using..?? I have a D'trax Zephyr, and ALL my locos can go nuts if the short is not fixed quickly....I think this is a problem with all DCC's...
  3. radar

    radar Member


    I have a proto 2k GP-7.with sound and going through the manual that came with it plus the 255 page manual from walthers.com. there is no C.V to do what you need my prodigy when it shorts the sound quits and the loco dies till the short is cleared

    Attached Files:

  4. eric halpin

    eric halpin Eric Halpin

    DCC shorts

    I am running Digitrax Empire Builder. It works great but this one loco sure gets its shorts in a knot with a short on the layout. I am thinking there must be some cv that will tone down the sensitivity a bit.
  5. What kind of decoder?
  6. UP SD40-2

    UP SD40-2 Senior Member

    All the factory installed DCC w/sound decoders in P2K's are QSI:winki: .

    I too have checked this, and like Dave mentions, there is no CV for this:cry: . i went and checked the specs on the other sound decoders i have for a setting for this also, only Loksound has 2 that MIGHT help with that, and thats only a might.

    Eric, i have MANY engines with QSI and fortunately i don't have this problem, so i am kinda baffled:confused: . one thing you might want to try, i have done on my dads layout, put isolated rail joiners on your engine holding tracks, just hook them up to a toggle switch, when you want to use the engine, flip the switch, solves lots of problems:winki: .

    Just a thought:winki::smilie:

    :deano: -Deano
  7. Gary Pfeil

    Gary Pfeil Active Member

    I've had the same type problem with various decoders over the years. Digitrax DH120's, Soundtrax board made for Bachmann 2-8-0, and most recently a decoder of unknown make (haven't opened up the model) in a FM unit I bought from a Canadian hobby shop. CFM something or other.

    The Digitrax decoder I simply replaced, and I had no further issues with that loco. The soundtrax I have done nothing with, it only rarely acts up. The other I just received so haven't decided what I will do. But it started runnig backwards at full speed so needs attention.

    I have a rather large layout and had not seperated it into multiple blocks, so a short anywhere affected the entire layout. I just changed that, using Tony's power shields I have divided the upper level into 6 blocks, will work on the bottom level in the future. For now, I have tested the system by causing shorts in various blocks and am pretty convinced that locos in other blocks are not seeing any kind of spike or whatever it is that causes the reactions we are speaking of. Of course if a short occurs in the same block that a problem loco is in, the problem may still exist, but so far (only a few hours of operating) no problems. I am just starting my engine facility area now, and plan to do as Deano suggested, be able to turn power off to individual tracks.

    I'm sorry I can't offer any other help, I do not think there is a cv for what you want.
  8. eric halpin

    eric halpin Eric Halpin


    Thanks for your comments. The problem is not too big a problem for me as it seldom happens anyway and NEVER happens unless a short arrives in that block. I suspect what I am hearing is a built-in protection for the Quatum sound unit in that if there is a voltage spike (21.5v+) as can occur on a short the sound system alerts you to the issue with these horns tooting! I am not sure why this one loco does it as the three others never have done it so I presume its cvs are set a bit different. I shall investigate that end someday I hope.


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