Problem with MTH SD70AC KATY alway CV55=5 to power up

UnionPasific Jun 2, 2011

  1. UnionPasific

    UnionPasific TrainBoard Member

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    Hi All,...

    I have 3 MTH SD70Ace Katy and all have problem with sound, the sound can not came out before we reset to mfg default, like example, when i put on track,..then i turn on F3 the engine can not on,...until i do CV55=5 the i press F3 the engine can on and everything going to normal,..until i shutdown engine by F3 again,...and the problem occur,.i must do cv55=5 the press f3 gain to power up engine,..

    Does anyone can help me please?

    regards
    adhin
     
  2. Geep_fan

    Geep_fan TrainBoard Member

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    My old MTH ACe was always VERY picky about CV's and stuff like that. MTH dosen't exactly use the regular NMRA standards for DCC.

    You could just leave the engine running, railroads really don't shutdown the equipment manually anymore and they just use the auto shutdown. Leave the engines idling for now.
     
  3. UnionPasific

    UnionPasific TrainBoard Member

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    oke ,...i will try to make longer in idle. yes it probably there is a batere super cap to supply the Microprocessor.
     
  4. jalajoie

    jalajoie TrainBoard Member

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    This is a known problem with MTH sound locos. MTH will ask you to send the unit for service.
     
  5. UnionPasific

    UnionPasific TrainBoard Member

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    They ask me to do change the super capacitor from MTH, they will send it, but i'm not sure that the problem, because i replace super capacitor with live batere to supply the Microprocessor, the problem still occurs and i have conclusion the problem is not occurred from super capacitor but inside the Microprocessor during programming or something block the latching system of Microprocessor.
     
  6. UnionPasific

    UnionPasific TrainBoard Member

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    solution for prime over problem MTH HO SD70ACe KATY

    All,.Good news

    I had been contact with MTH support and they suggest to change the Super capacitor and the result is 100% solve,..i hope this can issue can help another person who has same problem like us,..just change the 2 super capasitor which are black color with new one, i hope i can attach the picture,

    [​IMG] [​IMG] [​IMG]
    we have conclution that super cap have leak inside body and can not discharge slowly soo can effect to Chips during supply power off.

    Thanks for support.
     
  7. ken G Price

    ken G Price TrainBoard Member

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    Thank you for the follow up information.
     

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