First Try with a DCS decoder - Bad Decoder???

kverdon Jun 22, 2012

  1. kverdon

    kverdon TrainBoard Member

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    So I tried an install of a DCS CN decoder in a Atlas Classic RS1. Though I followed the instructions to the letter I've got a major issue. When I put the loco on the track it takes off like a rabid hare with no input from the throttle. I've tried putting the unit on the programming track and programmed it it an new address. It flashes and moves on the programming track but when back on the main track it still ignores the new address and zips off down the track. I've tried playing with CV-29 to disable the analog conversion but no go. Though it seems like it responds on the programming track, when I put in on the mainline it just scoots off at warp 9 with no ability to control it. I've done a decoder reset etc, etc it just does not seem to work. Do I have a bad decoder? I so I may have to rethink DCS in the future. 0 for 1 are not good odds :-(

    Kevin
     
  2. lexon

    lexon TrainBoard Member

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    So it is a known issue that DCC and DCS do not like to play together.
    What brand DCC system are you using?

    Rich
     
  3. woodone

    woodone TrainBoard Member

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    You said that you used a CN decoder. So I guess that you are working in N scale. And the decoder is a TCS CN decoder. If this is correct you have DCC decoder.
    Like Rich asked what system are you using?
    I am guessing that you have a motor brush wire or tab touching the frame some place. Did you use Kapton tape over the brush caps where you attached the orange and gray wires?
     
  4. kverdon

    kverdon TrainBoard Member

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    Sorry I meant to say TCS (DCS make the flight sim I'm enjoying..) Yes, this is an N-Scale TCS CN in an Atlas N RS-1. I did place a ring of Kapton tape all around the end of the motor with the brush caps as illustrated in the directions. After talking to TCS today I found out that even if you do this and follow their instructions to the letter, you still may have a scenario where the motor shorts the frame due to the tight fit. This may also explain why we have never seen a DCC ready version of the RS-1.... I went out and purchased a new multimeter and sure enough I had a short between the motor and one side of the frame. The fix for me was to put a second, narrow, ring of Kapton around the other end of the motor as well as the brush end. You have to make it wide enough to insulate the motor but not touch the armature or the flywheel. This fixed the short but the decoder was already toast so its going back to TCS for repair/replacement. Well at least I'll be better prepared for the next 2 I have to do.

    Kevin
     
  5. SteamerJ

    SteamerJ TrainBoard Member

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    I have an Atlas RS11 that I put the TCS decoder in and it runs great. Once you get it installed correctly you should be very happy with it. I love TCS decoders.

    John
     
  6. SteamerJ

    SteamerJ TrainBoard Member

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    I meant RS-1 the RS11 was a typo!

    John
     
  7. woodone

    woodone TrainBoard Member

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    Sometimes you might have to use a Dremel tool to make alittle more room at the brush holder in the frame.
     
  8. lexon

    lexon TrainBoard Member

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    Meter Dremel

    Great idea on the meter. Some never do that and are new to DCC. I tell anyone who want to work at this level in DCC, get a cheap digital multimeter. They do quite well foe model railroading. I paid about $4.00 each from Harbor Freight. I have had three for some years and compare quite close to the expensive meter and so much cheaper to replace if mis-used.

    I had to mill out a diesel frame with a Dremel a little for clearance with a motor with a layer of Kapton. It did not take much milling. My LHS, local hardware store sells a wide variety of Dremel bits.
    I used nylon screws to secure the motor as both motor frame halves were tied to the brush on each side. The multimeter told me this before finishing the install and powering up.

    Rich
     
  9. Arctic Train

    Arctic Train TrainBoard Member

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    Hi Kevin,

    I've installed a slug of CN-GP decoders in older atlas locomotives and yes they are a holy bugger to install correctly. I had similar experiences as you and found out that once the locomotive hits the track if it takes off like a banshee the decoder is now toast. Testing with a multi meter is a must before you apply any real voltage. I love the way these decoders perform though when they're installed correctly. All I can say is take your time and isolate, isolate, isolate, then triple check to make sure the motor is isolated.

    Brian
     
  10. kverdon

    kverdon TrainBoard Member

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    Thanks for all your replies, it gives me hope that I'll get these sorted out in the end. Another tip that the TCS tech gave me was to place a piece of Kapton Tape on the underside of each Decoder boards as you can get a short there as well.

    THANKS all,

    Kevin
     
  11. kverdon

    kverdon TrainBoard Member

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    Well I'm now 1 for 3 with these guys. Did #3 exactly the same as #2. Isolated the motor at both ends with Kapton, Kapton on the bottom of both boards. Tested with the meter to make sure that the motor was not shorting the frame x2 on each side and still, when I put it on the track it crept (not ran off) for a few inches with no throttle and died. Sending these 2 back to TCS, hope they have a quick turnover.

    I'm starting to feel that TCS stands for "Totally Cursed Systems"......

    Kevin
     
  12. DCESharkman

    DCESharkman TrainBoard Member

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    Not really a good way to think. TCS is well known for their customer support and the Goof Proof warranty. There is still a possibility that the solder to the brush caps is part of the problem.

    Since you are new to the decoder installations, it takes time to get the real knack of the installs. After doing over 500 decoder installs, I have no issues with them. Even still, the CN GP came out afterwards, and I had only a limited experience doing them. I did fry the first one I tried. The second one went better, and now after about 50 of them, they are second nature.

    It is all about building experience, and as they say, Experience costs plenty.
     
  13. mfm_37

    mfm_37 TrainBoard Member

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    The key to getting those motor connections isolated is to get the cross section of the wire and solder as thin as possible. I tin the cap and the wire first. Then flatten the tinned wire end with a pair of needle nose pliers. The touch the wire to the cap apply enough heat to get the tin to flow and it's done. Still need kapton tape to insulate.

    Martin Myers
     
  14. kmcsjr

    kmcsjr TrainBoard Member

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    I've never even been a little bit tempted to go HO. Especially with N and O in the house, my wife insists there will be NO HO in our home. That said, I can see the allure of having a huge cavern inside the HO shell, for the teeny decoder. Stick with N and DCC! you will enjoy the end result.
     
  15. SOUPAC

    SOUPAC TrainBoard Member

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    I’ve found their performance, and especially the jack-rabbit starts, are greatly improved by simply turning off the BEMF.
     
    Last edited by a moderator: Jun 27, 2012
  16. woodone

    woodone TrainBoard Member

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    You are going to blame the decoder before you know just what is wrong?
    Is it possable that you have installed it with a wire touching the frame?
    This is NOT a plug and play install! You have to make sure that the motor wires don't touch the frame! I always use a Dremel to make a little more room around the motor brush caps for the solder connections.
     
  17. mfm_37

    mfm_37 TrainBoard Member

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    Before installing another decoder, build a current limited test track. Get a 100 ohm, 1/2 watt or larger resistor. Connect the resistor in series in one of the track feeds. Radio Shack sell a 5 pack for $1.19. Now use this current limited track to test run the decoder. Do not put the engine on a non-limited track until it runs properly on this test track. That resistor will save decoders.

    Martin Myers
     
  18. colprit

    colprit TrainBoard Member

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    Kevin so far I've tried three different locos a plymouth Shunter which i got to work for a while but the wheel wippers are playing up, this had a digitrax 125 wired chip in other two I'm still having problems with. They are a bachmann 4-6-6-4 articulated which in the end I sent away to be done this also had the same chip , but when it came back the pins in the rods decided to keep popping out so I've giving up on it. The other one I am doing at the moment is an old atlas/kato u25b which is a tcs decoder split board type, the second one the first one was faulty, I done exactly as it says in the instructions on TCS website but I am still unable to get it going. I find this really annoying as I want to be able to do these myself and not spend money paying others to do it.
    colin
     

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