Hi;
I just installed a new Digitrax DN123K3 decoder in a Kato NW2 and am having problems. I put it on the track before any programming to make sure it worked. It did, it ran 1/2 way around the layout and stopped. I picked it up and put it back on the track at the point it had started running and the lights started to flash. My Digitrax Zephyr indicated a short. I checked the motor with an ohmmeter and found no short indicated and the motor was isolated from the frame. I then put it back on the track and the loco's lghits stopped flashing and the Zephyr no longer indicated a short. But, now the lights won't light nor will the engine run. Did I smoke the decoder? I saw no smoke or flames and the decoder wasn't hot to touch. Help please! What can I do - What should I do? Thanks,
Tom Mann.
Sounds liek the decoder is probably blown. But check the loco first - put the original board back in and see if it runs on DC. If you got a short indication after it was running, something slipped and touched where it wasn't supposed to - about the only loose pieces in that loco are the motor clips. If one shifted back or front it could have touched an adjoining solder pad on the decoder board and caused a short. Did you put the piece of tape on the frame as shown in the instructions to keep the decoder board itself from shifting around?
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Tom,
The decoders are probably loose in the frame. The Digitrax boards tend to be thinner that the stock boards. You can add a little solder to the pads that slip into the frame or shim the board. My preferred method is to shim with a small piece of sheet brass cut from a left over etched part fret.
The decoders may not be blown, but can't tell until they make good contact. That's why the one went 1/2 way then stopped. The loose board shifted. Take the shell off and it shifts back.
Once you get them back together, check them on a program track first. If you can read the address and CV29, then put them on the powered track. Can't blow a decoder on the program track.
BTW, Loved the weathering book.
Martin Myers
Martin and Randy;
Thanks for the replies. I re-installed the original board and the engine runs fine. Guess I'll get a new decoder. I did shim the decoder with Kapton tape as suggested and the decoder was quite tight in it's slots. I will try solddering the next one tho'. (At least put a little solder on the pads tom make the board "Thicker"). They must have lots of people with trny hands, to put this loco together at the factory.
Thanks again,
Tom Mann - P.S. Martin, I am not the Tom Mann who you are thinking of who does superb weatherins and writes books.