Digitrax decoder and kato p42 (N) problem ...

[Nataraj]

Ok... so Ive had one kato p42 for a while, equipped with a digitrax drop in decoder. Trainworld was having a sale so I picked up 2 more recently, and ordered 2 digitrax decoders from my LHS. Now here is where my problems start. Digitrax has "upgraded" these decoders since I bought my first one - the electronics on the board obviously looks different, and the LEDs have changed from orange when not lit to clear. The engine runs rough, and sometimes wont run at all (only lights). With the stock PCB it runs smooth as butter on analog, but soon as I put the decoder in it runs like crap on DCC.... I even swapped the decoder for my old one and the engine ran fine - so I know its not the engine. I tried everything but I cant get it to run smoothly. If it does start to run it runs for a foot or so then it stops - then I have to nudge it to get it to move again.... Anyone else have this problem? Or possibly a solution?

[wm3798]

 Sounds like a motor contact problem.  Double check the motor brushes and make sure they're making solid contact with the tabs on the decoder.  If all else fails, send it back to Digitrax with a copy of the receipt, and they'll send you a replacement.  You can find their warranty form online at their website.

Lee

[mfm37]

 As Lee pointed out, sounds like a motor contact problem. I shaped the two brass motor contacts so that the ends that go under the gray clip were curved upward at the clip. Once that clip is installed, the extra spring pressure keeps them in contact with the decoder pads.

Martin Myers

[rrinker]

 Something else I've seen posted to help this situation is putting blobs of solder on the contact pads. Either the decoder PC board got thinner or the chassis slot for the board got thicker, either way the result is less solid contact than before and a little tweaking is required.

                                             --Randy

 

[Nataraj]

Thanks for the help guys! The motor contacts do seem to be the problem -I can see a small gap underneath the contacts. Im also pretty sure the board got thinner (probably cost cutting...) because its more flexible than the older one. The engines seem identical, even the part #'s for the shells are the same. I think ill eventually solder the contacts to the board.... Thanks again! Nataraj