Have recently converted from RailCommand to NCE DCC and am in the process of converting loco fleet to new decoders. Have installed 9 DASE in various Atlas and Kato engines and all have worked perfectly except for one. When I went to program it I didn’t get the usual readout and page mode appeared to come in to play. I called the good folks and NCE and they said send them the decoder and they would replace it, which they promply did. Installed the new decoder and guess what, same thing happened. Smelling a rat I removed the decoder and put it in another Atlas RS-3 and it worked fine. It appears to be the engine but for the life of me I can’t find any thing wrong with it. Any thoughts or similar experiences?
Sometimes the same type and manufacturer of a loco can have subtle changes from edition to edition. Also, was this a used unit…could the previous owner have “modified” the wiring a bit, or added pickups? Just a thought.
Anyway, I suspect you have a wiring “issue” somewhere. I don’t suppose a wire was inadvertently switched by the assembler, and you have not actually traced them to see if the colours are all going to where you thought the others in othe locos had gone?
Have you actually checked continuity in all wires, throughout their lengths?
Since you’re sure the decoder is good, one test that might be worth trying is to disconnect the motor leads and substitute a 5 to 10 Ohm power resistor so the decoder thinks there is a motor connected. If the decoder can be programmed, then the problem is with the motor. The next thing I would check is to insure that the motor’s brushes are totally isolated from the frame.
Clay - does the decoder work in the suspect engine BEFORE you tried to program it? (i.e. under default factory settings?).
I had a somewhat similar problem once and it turned out to be a wiring short in the engine itself. From your description, it sounds like it has to be the engine itself.
Since you know the decoder works in the Atlas RS-3 it must be good. The problem is in the engine that the decoder won’t work in. You probably have a short either being the motor brushes or possibly the motor may be touching the metal frame somewhere.
Also trace your wires and make sure they are wired correctly. Could also be a wire is touching metal somewhere.
Thanks for the reply’s. If memory serves me, I believe I took a RailCommand receiver out of this engine but am not entirely certain. A short in the engine itself was my first thought but a visual inspection did not show any. I guess my next step will be to remove the motor and make sure all of the wiring is as it should be. I think I will also get out the old DC power pack and see if a quick connection to it yields any result. I did reset the decoder but only after I had reinstalled it in to the other engine. Hopefully can post some results tomorrow.
I’d poke around with an Ohmeter, making sure each decoder connection goes only where it;s supposed to. Also, maybe the motor is drawing more current than it’s supposed to, which can be checked by measuring current with the motor stalled using DC.