Decoder problem Stewart U25B & F3

Has anybody else had problems getting decoders to work in either of these locos. I’ve tried a TH150DP, a DH163IP, a DH123PS, in both the U25B and the F3. Nothing no lights, no power, zippo. And Stewart/Browser is very slow at answering and Digitrax says it their problem. I use the Prodigy Advnaced system, I checked it by re-programming a Proto GP30, works fine.

I don’t have a U25B, too new for me, but I have an F7. Is your F3 the Stewart or Kato drive? Based on the decoders you are trying to install, I’m guessing the Stewart drive, with the board that has an 8-pin socket on it for the decoder. I installed a TCS T1 in my F7, made my own 8-pin plug. Any of the decoders you mention should work in this loco. First, do you still have a DC power pack that you can verify that they run good on DC, with the jumper plug installed in the 8-pin socket?
Next, try one of the decoders. If you use one of the Digitrax ones, put the loco othe program track and see if you can program CV08 to the value 08, this is the factory reset. Doy ou get ANY response to programming? If the Prodigy Advanced supports multiple programming methods, try using Paged Mode. Try reading basic information such as CV01, the short address, which should be 03 after the reset. If you can read CV values , try running the loco on the main using address 03. If that works, then it’s back to the program track to set up the real address you want to use.

–Randy

I have installed NCE decoders in Stewart U-25B’s. I wired directly and did not use the plug. My U-25 didn’t have a plug anyway. My installation went fine, and these are some of the best running engines I have seen to date. Best of luck.

I just installed a TCS MC-2 decoder into an F3 using the medium plug socket that is available. My installation worked just great. Are you using the NMRA plug, or have you removed the Stewart board and hard wired the loco?

Have you thoroughly cleaned your locomotive wheels and track? A decoder is not a cure-all for proper wheel and track cleaning – DCC might even be more susceptible to these problems. If the locomotive doesn’t run good under DC control because of dirty wheels or dirty track, DCC is just going to complicate these problems.

If you have locomotive with the Kato chassis, go with one of the board replacement decoders, such as NCE has. See Tony’s website for more information.