New to DCC decoder installation????

Dave Howie Feb 13, 2018

  1. Dave Howie

    Dave Howie New Member

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    I was old school DC way way back. Just started up again and going all DCC in N scale. Are there sites that give step by step decoder installation. I tried last night to install a decoder in an Atlas GP 38. Got every thing installed but the loco will not respond at all. No lights no movement. Any suggestions welcome
     
  2. SP-Wolf

    SP-Wolf TrainBoard Supporter

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  3. RBrodzinsky

    RBrodzinsky Staff Member TrainBoard Supporter

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    Rule 0 of DCC decoder installs: KAPTON TAPE IS YOUR FRIEND. Literally, the only thing you want touching the frame or strips are the rail power pick-up wires (or pads) of the decoder.

    The TCS installation pictures are some of the best out there. Also, Spookshow's database has some good photos of loco innards, even if not specific instructions. Also, use the search function here on TB; there are lots and lots of old threads where folks post photos of their installs.

    You don't say which decoder, so difficult to give guidance on what to look for at this point.
     
  4. woodone

    woodone TrainBoard Member

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    There are several things that can go wrong with Atlas N scale DCC installs. First is the way most decoders make the decoder to motor contacts. The two motor tabs just stick up an make (you hope) with the decoder. Second is the thickness of the decoder. Where the decoder fits into the slots of frame the decoder is not thick enough to make contact.
    Put a small dab of solder on each tap where it slides into the frame. This will make the taps a bit thicker and now will make contact with the frame. For the motor will depend on who’s decoder you are using. I solder a short jumper wire from the motor to the decoder.
     
  5. wombat457

    wombat457 TrainBoard Member

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    I am with others, TCS Decoders are the way to go and come with very clear easy to follow step by step instructions. I was like you and very apprehensive about doing decoder installs until I started using TCS decoders.

    What might help people to work out your problem though is what type/make of decoder did you use?
     
  6. jdcolombo

    jdcolombo TrainBoard Member

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    If you are installing a board-type decoder (rather than a hard-wired decoder), the usual culprit if the engine is not responding at all is the contact between the decoder and the frame "fingers" that are supposed to contact the power pickup pads on the decoder. As someone else has already pointed out, you can cure contact problems by putting a thin coat of solder on the pads until the decoder is "tight" under the frame fingers. if the pickup pads are only on one side (top), you can also try using some .010 sheet styrene underneath to tighten things.

    If the decoder responds (e.g., headlight comes on) but the engine won't move, the usual culprit is the contact between the motor pickup strips in the center of the frame and the motor supply pads on the bottom of the decoder. You can try to bend the decoder pickup strips upward to put more pressure between the strips and decoder (and make sure that the ends of the strips are actually contacting the pads and aren't skewed off them). A better solution is to hard-wire the pads to the strips, but this makes for a more difficult installation.

    If you don't have an electrical multimeter, get one, and make sure that it has a continuity check setting. You can use the continuity check to make sure power gets from the rail through the wheels, through the frame to the decoder and also to make sure that nothing is shorting from one side of the frame to the other or from the frame to the decoder. You can get a perfectly useful multimeter for $25 or less from places like Lowe's or Home Depot.

    While the theory of "drop-in" decoders is great (easy installation), the practice is much more variable. The drop-ins often aren't as easy to install as you might believe (e.g., the frame halves need to be separated to take out the old light board and slip in the decoder) and they often need tweaks as outlined above to work. And then even after all this, they will one day mysteriously stop working and need additional tweaks. I've found that by the time I'm done with the installation process and these tweaks, I could have hard-wired a small motor decoder like an ESU LokPilot V.4 (my favorite) or a Digitrax DZ series or a TCS M or Z2. If the engine already has a light board, I use the factory board for power-pickup for the hard-wired decoder and also re-use the LEDs by cutting the board traces and then wiring the decoder's headlight and rear-light function wires to the now-cut LED circuits. And the advantage of hard-wiring is that you know everything has a solid electrical connection . . . forever.

    John C.
     
  7. hoyden

    hoyden TrainBoard Supporter

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    John C., thanks for those observations; drop-in vs wired. After installing many drop-in decoders over the years I am having to work through the problems you enumerate.

    Also, I never put a newly installed decoder locomotive on the main track right off. The new installation goes on the programming track first. I won't put it on the main until it passes the programming track.
     
  8. Dave Howie

    Dave Howie New Member

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    sorry should have included it was AMD4 DCC drop in. You are correct on the kapton tape TSC show it as a required part of installation
     
  9. Dave Howie

    Dave Howie New Member

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    Thanks for all the advice DCC seems the way to go just a steep learning curve
     
  10. wombat457

    wombat457 TrainBoard Member

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    I'll tell you what I was told when I first ventured into this DCC monster - "Don't over think it and stick to the basics to start with". I think the hardest part of DCC is understanding/knowing what equipment is needed for what and how it all goes together.

    As far as decoders are concerned, I prefer TCS. The main reason is because they have VERY clear instructions on their site for the installation of their decoders for each specific Model and Make of train they produce decoders for, complete with very clear pictures of an install.

    I don't know if this applies to all "Drop in Decoders" (I assume it will) but the Kaplon Taper is need to insulate the brass pick up strips from the brass tabs that connect to the Decoder. If you don't do that or do it properly, you will fry the decoder, as I inadvertently did last night on my Kato F7 B Unit.
     
  11. jdcolombo

    jdcolombo TrainBoard Member

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    The ease of frying a drop-in decoder if you don't properly insulate it with Kapton tape is another reason I quit using them. The hard-wire decoders are almost always wrapped in some kind of plastic, which keeps them safe unless you make a wiring mistake. Not so with the boards, which can contact the frame and result in immediate death (for the board; only sadness for you). Honestly, I bet I can install a hard-wired decoder in an engine with a factory light board and have it working in about the same time it takes to properly install a drop-in and get it working correctly. The "drop-in" name should be changed to "kinda, sorta, drop-in" :)

    John C.
     
  12. wombat457

    wombat457 TrainBoard Member

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    Your right about the "if you don't insulate properly" with drop in's; however if that is done as per the instructions supplied (can only reference TCS) then it only takes 5 minutes to properly install them and have the engine running and running properly. At least that is what I found when I did my two Kato ES4400AC's.

    With that being said, if you are very experienced at doing the hard wire variety it may not take you (figuratively speaking) long at all.
     
  13. jdcolombo

    jdcolombo TrainBoard Member

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    If the drop-in actually works, it is indeed easier than a hard-wire and really is a 5-minute job, which I can't match with a hard-wire. The problem is (or was, since I don't use them any more) that about half the time they did not work without some tweaking. In these cases, the process was as follows:

    1. Take off the shell.
    2. Find that to take the old lightboard out and put the new decoder in, frame must be separated.
    3. Separate frame.
    4. Install new decoder board.
    5. Reassemble frame.
    6. Put engine on track; find that it is unresponsive.
    7. Track down reason for unresponsiveness. Almost always relates to contact between frame "fingers" and power pickup pads.
    8. Separate frame again to get decoder out.
    9. Add a coat of solder to the pads.
    10. Find that solder coat is too thick. File down solder coat until decoder fits under fingers tightly.
    11. Reassemble frame.
    12. Put engine back on track; find that light works, but motor is unresponsive.
    13. Separate frame again. Take decoder out again.
    14. Bend motor contact strips upward to put more pressure on contact area with pads on underside of decoder.
    15. Reassemble frame.
    16. Put engine back on track. Everything works! Great!
    17. Put shell back on. Done (finally).

    The problems I experienced were almost always with Atlas engines and Digitrax drop-in boards. The TCS drop-ins may be more reliable in their thickness, and I suspect that Kato's frames have better tolerances, meaning that it is less likely a drop-in won't properly contact the frame. Some Kato engines also have their motor contacts on the outside, so that they fit over a pad on the side of the board rather than make contact underneath - and this system is far more reliable, IMHO, than the underneath kind.

    If a drop-in works first time, it's great. But my experience was that the drop-in too often did NOT work on the first try, like the OP. Then it was a pain. So I finally just gave up. My hard-wires work the first time, all the time (as long as I've tested the decoder itself before installation - occasionally you get a dud).

    John C.
     
  14. wombat457

    wombat457 TrainBoard Member

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    John,

    If you had that much trouble with the drop ins I don't blame you for discarding them, I would as well. As also mentioned, the only decoders I have experience with are the TCS and, thus far, only in Kato engines.

    One of the TCS decoders I installed, into a Kato P42 had the "drop down contacts" and they were easier to work with and did give a good contact without soldering or any other work. If all decoders could be like that, life would be much easier.

    One thing that would turn me off drop ins is the need to separate the frame? The Kato engines decoder sits on top of the engine and (at worse) slides into a couple of slots. Slide the old decoder out, slide the new decoder in, solder the motor tabs to the decoder, replace the shell/body, end of process. Very quick and very easy and nothing compared to what you have described above, my keeping in mind that you are referring to a different manufacturer of both engine and decoder.
     
  15. jdcolombo

    jdcolombo TrainBoard Member

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    Yes, the Atlas frames (at least the GP9 and RS11) don't have the "slide out" design. The board is "locked in" between the front and rear fingers. Sometimes you can get it out by just loosening the frames screws and pulling the frame partially apart, but more often than not I'd loosen the screws too much and the frame half would come off anyway. The Kato design is far superior. I guess that's why they are Kato!

    John C.
     
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  16. wombat457

    wombat457 TrainBoard Member

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    By the by ... you might pay a little more for Kato engines but in the long run they really are worth it.
     

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