" A CONTACT PROBLEM INSIDE MY LOCO"

[TrainsRMe1]

Hey ALL,                                                                                                                I just installed a decoder in my SD 70Ace and AC4400 and the problem now is that the lights would flicker BUT, there wouldn't be any movement!  well actually in the SD 70Ace the lights would be on steady, but NO MOVEMENT, in the AC4400 I would have to (get this)with the shell off I would have to press on the sides of the contact points on the decoder to get electircal  contact to the motor,  I'm hoping it's just real dirty contatcs, because the decoders are new, the decoder is made by DIGITRAX, AND IT'S A DGTDN1631C Nscale,                                               Thanks ALL,                                                                                                             Have a continued great Summer

[BigDaddy]

TrainsRMe1

DN1631C

According to the Digitrax site, these are for Intermountain locos.  Kato makes both models you have but the recommended decoder is a DN1631K1C

[mfm37]

Blinking lights indicate a short circuit. Did you install the included kapton tape on the frame per the instructions?

[rrinker]

 And intermittant contact is a fairly common issue it seems on newer N scale locoos - the slot int he frame where the circuit board goes is wider than the decoder circuit board is thick, so the parts of the board that are supposed to touch the frame to get the track power into the decoder do not make solid contact. Adding small blobs of solder on those pads is a common solution. 

                          --Randy

 

[bavrail]

I agree on the solder blobs. That seems to be a common problem. 

I've also run into one where the motor tabs on the decoder were too short to keep the lower motor contact in place securely. I had to solder the lower motor contact to the decoder tab. (The motor tabs on the original light board were much longer than the ones on the decoder).