Decoder goes full bore...

Discussion in 'DCC & Electronics' started by kchronister, Dec 1, 2004.

  1. kchronister

    kchronister Member

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    So I have a decoder installed that I think I may have fried. Initially I didn't have the motor isolated -- I did all the right things, but was sloppy and didn't test before trying it out. The thing didn't work at all and when I tested the motor wasn't isolated -- I think I must have had some oil or grease on the nylon motor mount screw that was conductive, because when I cleaned it off the conductivity test was fine...

    Now that the motor is isolated, the loco works under DCC, but there's no throttle control: It's off or it's full bore. Since I know DCC works with full power on the tracks at all times and the decoder modulates it in pulses to achieve lower speeds, I suspect this means the decoder has blown out... Anyone know a way to test this effectively? Anyone have alternative thoughts -- maybe I connected it wrong (but I doubt that, I triple-checked and I've done more than a few of these now)... Or anyone able to say "yes, it's shot, too bad?" definitively?

    Thanks,

    Kris
  2. moria

    moria Member

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    Hey Kris :)

    what loco and decoder?...

    if you say DZ123 or DZ143 or Atlas loco with replacement board such as DN163A0 or NCE equivalent I may have an answer, or at least a place to start looking... :)

    Do the lights work at all ?

    Regards

    Graham
  3. kchronister

    kchronister Member

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    It's an old Mantua 4-6-2 with an open frame motor. I used the most basic Lenz decoder (the 10000 I think it is). The light didn't work under DC (bulb burned out) so I didn't even hook it up, just the motor leads.

    Kris
  4. moria

    moria Member

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    Hi Kris :)


    Sorry, no idea, but your origional theory of blown sounds possible as there wa a short across the loco.

    Personally, I would see if I had a motor from another loco somewhere and just hook the decoder up with power in and motor out to check before consigning it to the destroyed bin though.

    Even though the value line is not a free goof proof warranty, its still cheaper to replace at lenz, and if less than 90 days old.. who knows, they may find a decoder fault... not holding my breath though :)

    Regards

    Graham
  5. kchronister

    kchronister Member

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    Thanks, Graham. Testing in another loco is a good idea, I'll do that...