DCC Locomotive lights won't turn back on

Model Railroader Electronics and DCC
1

Hi all,

I just got started with an N scale layout today. I have a basic oval track section for right now and just got my first locomotive and got it running today.

I’m using Atlas code 80 track with a Digitrax Zephyr DCS 51 all in one command station. Everything was working fine, my loco’s light was on when track power was on and the reverse light came on when I revered the loco. I put it aside for a bit and when I came back the lights are not working anymore.

The only thing I did was to change my loco’s ID so it wasn’t the default.

I have tried the obvious things, such as the light function key on my command station, but it doesn’t do anything. I also tried removing the power for a while but still no lights.

I even went and reset the locomotives decoder to factory settings using CV8, I know it worked because my loco id went back to 3. I also reset the Zephyr command station to factory defaults as well per the instructions on their website.

Anyone have any ideas?

Thanks,

Allen

2

Hi Allen,

This is a classic symptom of the speed step settings on the controller not matching the decoder. The decoder ships with speed step setting at 128. I think you’ve accidentally set it to 14. Try setting CV29 to 06. Refer to section 27.2 on p52 of your Zephyr manual and section 4.4 on p24 of the Decoder Manual.

Let’s hope that solves the problem.

Cheers

The_Ghan

3

Hello The_Ghan, thanks for your quick response.

I guess I forgot to mention it in my post last night, but I did see that in the Zephyr manual. And had tried that.

When I read the value of CV29, it was already set to 06. I actually changed it and changed it back to 6 just to be certain it was accurate.

Any other thoughts?

Thanks,

Allen

4

Could it be your decoders function circuits were damaged? I have one that did did opposite of yours. The lights stay on all the time and no matter what CV changes I make there’s never any change. It’s just the front light. Rear light works fine in all respects. The loco runs fine. It doesn’t matter what loco address is dialed in either. As soon as there’s power to the track the light is on. Like you I went through the whole gambit. Changed CV’s, reset the decoder, reset the system (Digitrax DCS50). No change.

5

Here is what the manual has to say about your issue.

  1. The DCS51 command station operates in 128 speed step mode. If you are

using a locomotive with a decoder that does not have 128 step capability

you will have to adjust either the decoder or the DCS51 so that both are

using the same number of speed steps to communicate. We call this procedure

status editing. You can status edit each individual decoder (see

Section 23) or you can change the DCS51’s system default by setting the

DCS51’s Option Switches 21-23 and run all of your decoders with fewer

speed steps to accommodate these decoders (see Section 28).

  1. If you can’t control the operation of the lights in your decoder equipped

locomotive with the DCS51, be sure that the decoder itself is programmed

to run in 128 speed steps.

Rich

6

I would read the Decoder Speed Step Settings section on page 40 of the manual as well.

http://www.digitrax.com/static/apps/products/starter-sets/zepx/documents/ZephyrXtra_flattened.pdf

It seems that the problem is miscommunication between the command station and the decoder as it relates to speed step settings.

Rich

7

I suppose this is possible, but how would I verify this? The locomotive came pre-installed with the DCC decoder, which is an NCE decoder per the website I got it from. There was very little documentation with the locomotive when I got it.

8

If the speed steps do not match, the symptom is the lights flash on and off as speed is increased or decreased - since the low order bit of the speed information is the F0 control in 14 speed step mode, so the lights would be on in step 1,3, 5, etc and off in 0, 2, 4, 6, 8, etc.

CV28 = 6 means 28/128 speed step, so the decoder is not set incorrectly. Zephyr reset means it should be back in default 128SS mode. The decoder rest also should clear any possible goof up witht he light control CVs and revert to standard directional headlights.

Should never ever have to play around with the status edit things to change speed steps, any decoder produced now or in the recent past can do 128 speed steps, and it’s not as easy to accidently get there on a Zephyr. I suspect loose connection, since it affects both front and rear lights, probably the equivalent of the blue wire that is common to both.

–Randy

9

Good point, Randy.

Did the loco come with a decoder or did you install the decoder yourself?

Rich

10

It came pre-installed with the decoder

11

As Randy suggested, it still could be a loose wire.

I just thought that if you installed the decoder yourself that the wire may be loose.

But, even a factory installed decoder could have a loose wire, so worth checking.

So, it sounds like you are back to the speed step setting issue.

Let us know what you find.

Rich

12

Bear with us, Allen.

As a new member, your messages are being moderated before they are posted, so we may be asking questions to answers that you have already suppllied.

Tell us more about the loco. Is it new or used? What type of loco? You mentioned that the decoder is an NCE decoder. How did you find that out?

Rich

13

The locomotive can be found here http://www.modeltrainstuff.com/Atlas-N-GP-7-Ph-1-CR-DCC-p/atl-40000440.htm

I bought it new from that website and that’s where I got the info on it being an NCE decoder.

It came with very little documentation, but there is a tear down diagram, so maybe I’ll look for some loose wiring when I get home today.

Thanks for all the help, I appreciate it.

Allen

14

So I got the shell off and what I find is a circuit board with LED lights soldered directly to them. So basically loose wiring couldn’t be the issue since there are no wires.

I sort of find it hard to believe that both LED lights would burn out together, but maybe that’s what’s happened.

I guess I need to contact the vendor or manufacturer and have them either fix or replace it.

Stinks though since this is my only locomotive, there is a show near me on Saturday. Maybe I can pick up another one there.

Thanks for all the help everyone.

Allen

15

If it’s an NCE decoder, than CV8=8 is not the reset. NCE decoders typically reset with CV30=2.

–Randy

16

Yeah, before I knew it was NCE I tried both. But just for good measure I tried CV30=2 again when I got home today. I actually did it three times in a row as suggested on some web article I read.

Thanks though

Allen

17

Allen,

I did a little research on the decoder. While I cannot be certain, my guess is that the factory installed NCE decoder is an N12A2, the recommended decoder for after-market installs in the Atlas N scale GP-7/9.

A few things to note about this decoder.

As Randy mentioned, the reset to factory defaults is CV30=2.

The first thing that I would do is to put the loco on the programming track and set the value of CV30 to 2. Then read the CV29 value to see what it is set to.

A value of 6 means that the speed mode is 28/128, analog DC is permitted, and a short address is assumed.

A value of 38 means that the speed mode is 28/128, analog DC is permitted, and a long address is assumed.

It may be that if the CV29 value is 6, that the lights will only be functioning at the short address of 03. I always make sure that CV29 is set to the long address on my locos, so I cannot tell you with certainty that the value of 6 will only work the lights on the short address. But it is worth a try.

If resetting the value of CV29 to 38 does not solve the lights problem, place the loco on a DC powered piece of track (you need a DC power pack to do this), and see if the lights work. Before I install a decoder myself, I always run a DCC Ready loco on a DC track to be certain that it moves in forward and reverse and that the lights work in either direction. Your loco has a factory installed decoder but it is designed to run on DC as well as DCC.

Here is what NCE says about the N12A2 decoder.

Always test your decoder installation on a current limited programming track before trying it on full track power. We recommend that the first “full power” testing be done on regular DC. The decoders should be driven by a good quality smooth DC power unit. Power packs with pulse power systems such as “tracking control”, etc. will give unpredictable operation. Analog operation is included in your NCE de

18

Well, I am happy to report that I have figured out the issue and my lights are now working again.

I must admit that I am quite embarrassed as to what the issue was.

After everyone’s diligent and helpful responses and several hours of trying different things, it turns out that I was trying to use Function 1 to turn the headlight on when in fact it’s Function 0.

So I don’t think I ever actually had an issue. I simply turned it off without realizing that I had and then was using the wrong key to try and turn in back on.

Well, l guess it’s a better thing than having a defective locomotive. And you can bet I won’t be forgetting how to toggle the headlights on and off ever again! [:$]

Thanks for all of your help though. It is very appreciated.

Allen

19

LOL

Allen, I for one, have been anxiously awaiting hearing back from you.

Kudos to you for finding the problem yourself and having the intestinal fortitude to report it on the forum.

Rest assured, we have all made some pretty DUH mistakes over time.

Glad it all worked out for you.

Now where is the photo of that loco?

Rich

20

For your viewing pleasure. With lights too!! [:)]