I think my kato SD90 is DEAD(can it be fixed)?

Discussion in 'HO Scale Model Trains' started by CRed, Jul 30, 2007.

  1. CRed

    CRed Member


    A while back I bought a Kato UP SD90MAC off of E-Bay.It came with a Digitrax decoder which I finally took out so I could test the engine on my DC track and it's completely dead,no lights,humming or anything.My son had tried to run it while the decoder was still installed so I'm wondering if that could have fried the engine?I would have thought that at worse that would fry the decoder,but I don't know because I know little about DCC.If it is fried is it even repairable?I'm guessing no unless I replace the motor.

  2. jbaakko

    jbaakko Active Member

    Have you checked all the wiring? Also, some quick plug equipped units require a jumper to run on DC.
  3. CRed

    CRed Member

    There's four wires leading from the trucks to the circuit board and they're fine.I also thought about the plug,but I don't see anything like that on the engine.There's a couple copper strips connected to the circuit board,but they're soldered on I think.

  4. green_elite_cab

    green_elite_cab Keep It Moving!

    If you locomotive's decoder is not set for analog control, it will just sit there. You would need to set CV29 to a certain value. I set all my DCC locomotives to 36 in CV29, which enables certain features, among them analog control. Many decoder have CV29 programmed for 6 out of the box, which should allow for analog control. My best guess is that someone programmed it to operat e acertain way, but left analog mode off for whatever reason. Try finding someone with a DCC set, and have them program the decoder to a CV that allows analog control.

    GO here. while you are there, you can also get a link to a long adress calculator, just so that if you ever want to run your locomotive on a DCC layout, it will be ready to go out of the box. this page also has a CV29 chart that should help you program it to work on analog.

    CV29 Look Up Table | Tech News at Tony's Train Exchange.
  5. CRed

    CRed Member

    So even if I have taken out the decoder I will have to do this?

    By the way,thanks for the help so far.

  6. green_elite_cab

    green_elite_cab Keep It Moving!

    No, if you take the decoder out, you will just need to install a jumper plug, which connects everything to where it needs to go.


    If someone has replaced the original PC board with a decoder on a PC board, then you WILL have to do this, unless you have the original PC board.

    if it didn't work with dummy plug in place of a decoder, then your engine probably does have faulty wiring. One way to check the motor is to completely remove it, then add power to it from the DC tracks. if it still turns, that means something is wrong with the wiring, in which case just redo all the wiring, double checking everything.
  7. CRed

    CRed Member

    I believe it's the original circuit board,it's an DCC ready model.Unfortunantly I do not have a dummy plug.

  8. green_elite_cab

    green_elite_cab Keep It Moving!

    ok, try this-

    make two sets of three wires soldered together. then tin the other ends of each wire, so that they don't fray, and stay solid. You are in effect making your own plug. place the locomotive on the table so that the front is towars the left. each pin has a number. the pins are numbered up counter clockwise, with pin 1 being the top left. 4 would be the bottom left, 5 the bottom right, and 8 the top right, simple enough. In fact, your PC board might already be numbered, which helps.

    now, take one set of three wires, and insert an end into the 1, 2, and 8. take the other set, and insert it into the 4, the 5, and the 6. the 3rd and 7th pins are left empty.

    basically, the pins on the top left corner should be connected, and the pins on the bottom right corner should be connected. do not connect the corners to each other.

    see if it runs now.
  9. CRed

    CRed Member

    You know,I was going to ask you about that.two problems though1)I don't have a soldering iron...and 2)Even if I did I wouldn't be good at it because Ive never done it before.I was thinking a wire for each pair would work,but I guess not.

    I guess I can take it into my LHS and see if he has some dummy plugs.

    Thanks for the help,it's appreciated.

  10. green_elite_cab

    green_elite_cab Keep It Moving!

    You don't Have a soldering iron? how have you lasted in this hobby!:eek:

    don't be afraid. Like airbrushing, soldering is one of those really simple things that people get really nervous over. If you can afford one, buy it, and some rosin-cored solder. You can find this stuff at Radioshack. Its also good to buy some flux, which further helps the solder melt onto wires and other connections. Ask the store attendant for non acidic flux, as some flux can start to eat through connections. I'll need to check the brand i use, but its to late at nigh now for me to run down and look.

    in any event, you strip some of the insulation off the wire, twise the copper strands together with your fingers, then dip the expose wire into the flux, if you have it (you don't necesarilly need flux, as rosin cored solder has flux in it already. it just helps to have seperate).

    the cool part is the solder will only go where you dipped the flux, so you just need to "drag" some off the end of the iron onto your wires!

    When it comes to wire soldering, you don't need to have any real skill, as you are just attaching the wires. Only in brass models and such do you need to be skilled at soldering, but we aren't dealing with that here.

    the only thing you have to do is to remember to clean the soldering iron before and after every use so that it stays clean, and then to also "tin" the soldering iron's tip when you are done with it, which means to cover it in solder, which helps protect the iron.

    Just make sure you grabe the handle the right way! i've "missed" the handle before and picked it up by the hot edge in front of the handle.wall1. hopefully though you have more commonsense then i do!

    seriously, don't be afriad of soldering. you can't be bad at it, because basic soldering really requires no skill. just practice on some scrap wire. its really easy, and after you've done it once or twice, soldering should come naturally.
  11. CRed

    CRed Member

    You have to remember,I've only been in the hobby for about 8 months.I only just got track a month or so ago and am a ways a way from having an actual layout for petes sake!

    Anyways,would it be possible for you to maybe make me one of these do-hickies if I were to reimburse you for the trouble?Either way,thanks a lot for the help!

  12. scottcn

    scottcn Member

    I'm going to second green_elite_cab's advice about soldering. It's not that hard. At least as far as soldering wires together goes. I haven't tried anything more than that.

    A basic soldering iron and solder aren't that expensive so you don't have much to lose by giving it a try (unless you burn off your fingerprints or something :eek:)
  13. green_elite_cab

    green_elite_cab Keep It Moving!

    I'd do it for free, because all i'd need is some scrap wire, and it would take longer for the iron to heat up then it would to solder them. In fact, i'd almost send you one of my old plugs, but the it occurred to me that Atlas is one of the cooler model railroad companies out there.

    simply go order a new dcc jumper plug!

    $1 each, not a bad price. all these plugs are standard, so you can use atlas's plug in your Kato one.



    trust me, its a valuable tool, and its easier then it seems. it will definitely help wiring your layout up.
  14. CRed

    CRed Member

    Thanks guys,I will most likely get one soon!

    Hey g_e_c,do you think you could give me a link to the plug?The one in your response is to a expired cart/check out.

  15. green_elite_cab

    green_elite_cab Keep It Moving!

    that is weird! i checked the link before, and it worked. I went now, and it doesn. its not problem though. Got to Atlasrr.com, go to their online store, and search "plug". it will be on the first page down a few items. It will be called "dummy plug for DCC"
  16. CRed

    CRed Member

    Duh!Yeah i can do that..I think.

    Thanks again!


Share This Page