I just installed a new NCE D15SRP DCC decoder in a new Atlas Dash 8-40CW Conrail Silver series (DCC 8 pin NMRA) locomotive. My layout is NCE PowerCab DCC.
When I place the locomotive on a track, it automatically starts moving at a good medium speed. I can select the locomotive at address 3, and I can control the headlights, but I cannot control anything less with the locomotive, including the speed. It just continues to go until I unplug the NCE PowerCab. When I plug it back in, the locomotive starts moving again.
Occasionally, hitting the direction button will short the NCE PowerCab. I've tried tweaking various CVs, including 29, and also reversing the direction of the 8 ping plug on the loco. I've also tried resetting the decoder numerous times, all had no effect.
Anyone seen this type of behavior before? Any ideas? All of my other locomotives work fine. Is this an indication that the decoder is bad?
Many thanks for any insight!
I think there is a short in the locomotive's 8-pin socket. Did you test run the loco without a decoder installed? If the decoder socket is soldered to a circuit board, make sure the pins on the bottom of the socket are not touching metal and shorting out the decoder.
I haven't been able to test it without the decoder because I do not have a DC power pack. I'm pretty sure the NCE PowerCab does not support DC locos.
I will check for shorts, thanks.
Welcome to the forums.
If you are going to do your own decoder installations, I think you should buy a cheap DC power pack. You should be able to find a used one cheap. It is almost a necessity to test a locomotive before installing a decoder to make sure it runs and that everything is OK before starting the instlation.
When looking for a short, look on the bottom of the locos circuit board to make sure none of the socket pins sticking through are shorted to each other with a bit of solder. Also, put a piece of electrical tape on the loco chassis under that socket.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
Thanks for that advice! I've chekced under the loco's circuit board and there is a piece of tape already provided by the mfger. I have another of the same locomotive arriving from a different source, so I'll give the decoder board a try in the new loco to see what result I get.
I'll also try removing the mfger's tape and seeing what is going on under the loco board (solder issues, etc.)
Much appreciated, guys!