Help with Athearn GP35

Model Railroader General Discussion (Model Railroader)
1

It has a digatrax 9 plug decoder in it .It will only go one speed and that is fast.I have a zepher DCC system .I can’t program CV 08

Is there a nother way to reset to factory values

Please help[:D][:D][:D]

2

Does your local hobby shop have a programming track? Do you have a friend that has one?

3

hobby shop is old school

4

Which decoder do you have in it?

If it’s a Digitrax Series 3 decoder (DH123-series or DH163-series) and it’s not resetting when you program 8 or 9 into CV8, then you probably have a faulty decoder and you should send it back to Norcross for replacement.

If it’s a Digitrax decoder from an earlier series, then nothing you do to CV8 will reset the decoder.

5

I’ts a NCE D13SRJ

6

For an NCE D13SRJ, you need to program “2” into CV30 to reset it. NCE uses a different CV to reset its decoders than Digitrax does.

TCS decoders will reset if you put “8” or “9” in CV8, or if you program “2” in CV30 (how’s that for playing well with others’ systems?) How to reset a decoder to “factory values” isn’t defined in the NMRA specs for DCC, so the manufacturers have a bit of freedom to handle it differently from each other.

I’ve had both NCE and Digitrax decoders that I’ve had to reset before they’d play nice, so my experience is that this isn’t unique to either brand.

BTW, in the case of Digitrax decoders, programming “8” or “9” into CV8 won’t actually change the value that’s stored in CV8. When you read back from CV8, it will return Digitrax’s manufacturer ID number.

7

Thanks for your help[:D][:D][:D][:D]

8

What do you mean by that?

9

Probably that they don’t have or know anything about DCC.

My LHS used to be that way, but they are learning - and have even converted their club layout (the club is associated with the store) to DCC.

10

Someone give me a step 1 for opening a Athearn GP35 RTR. It’s DCC plug ready and I have a NCE decoder for it. Just need to get it open. I’ve not seen any MFG that shows how to disassemble their locos.

Thanks for any help.

11

-tom

Take the couplers off and squeeze the shell above the fuel tank while lifting up on the shell and pulling the frame away. Should come right off

12

Thanks. Going to put er in now.

13

Tom, you can probably just remover the dynamic brake housing and drop the chip right in. May be no need to remove the whole shell. That’s the way our RTR GP35 was.

14

Got it working and reprogrammed CV01. I now have my first HO DCC engine. Wish I had the day off.
Thanks a lot. [:)]