I don’t know, but I believe that the original board didn’t include it
:
Thanks for post that, that is way more information than the short manual that came with the locomotive.
That is an old model Atlas (Lenz) decoder that was motor control only (no sound). The very first was model 340 with slightly upgraded versions under item numbers 341 and 342, all non sound DCC decoders.
Mark.
So I took the second unit that I have not tried to program, removed the dynamic brake cover and switched the jumper to digital. Put it on my track, set my controller to address 3, no response at all. I tried programming it with no repsonse.
It sure seems unlikey that two sealed units would both have bad decoders but it sure seems that way.
Have you tried using the last 2 digits of the running number? I have a vague memory of Atlas using this as the default instead of 3 many years ago.
Regards Jon.
Page 5 of the decoder instructions I posted talks about “power recycling” after trying to program, tipping the engine off the tracks for 5-10 seconds. Did you try that?
Have not tried that but I will.
Yes I did that.
I also forgot to mention that I removed the capacitor as well.
I have two old Atlas Gold B40-8s that had a similar set-up, moving the jumper made the decoder work on both. On mine, I believe (haven’t looked inside in a while) there were three rows of holes in the receptacle. You move the jumper from being plugged into rows 1 and 2, to being plugged into rows 2 and 3. No pins should be sticking out from the plug. (Note this is just a jumper, not a decoder, the decoder is more like a light-board replacement decoder.)
The fact that you can’t read anything back doesn’t mean it’s not programming, some decoders are like that. Sometimes adding a ‘booster’ will help (although usually that only applies to sound decoders). But anyway, maybe move the jumper and try setting CV1 to a number like 003 and see if the engine responds.
OP:
I had an Atlas engine (SD35) from that same production era, I never could get that factory-original decoder (the one with “the jumper”) to work well. The engine would run, but it was noisy with what seemed to me to be “interference” introduced by the decoder itself.
My solution was simple:
I REMOVED the factory decoder, and installed a replacement.
Since you seem to be getting nowhere, this is the solution I recommend to you.
The decoder you want is a Soundtraxx MC2H104at.
This is a NON-sound motor-only decoder, that has the exact same dimensions as the factory board – swaps out easily. It also has the same connections, should be an easy wire-for-wire replacement.
Although others in the forum would disagree, I always use the plastic “wire retainers” instead of soldering – makes it easier when you need to disassemble again. Because someday you probably WILL need to “get into it” again.
Also, I WOULD use solder to “tin” the ends of the wires – makes them stiffer and grips the retainers/contacts better.
Once I replaced the decoder, the engine now runs far, FAR better – smooth and quiet. I predict the same results for you if you go this route.
You are correct, I think the contacts should be soldered [:)]. I’ve fixed a number of locomotives that were running erratically because of bad contacts exactly there. Only a small amount of soldering is required, and removing it is very easy: just place the iron a few seconds on the contact and the wires are easily removed.
Simon
Just to clarify, do you have an NCE PowerCab or the 5 amp ProCab system?
And are you using the “use program track” option on the controller menu?
I also suggest that you find a seperate piece of track and temporarily connect your DCC system to it. That way you will remove any possibility of some extraneous source causing an issue. And you will also be able to connect a voltmeter across the tracks to see if your DCC system is actually putting out any power.
(it probably is, but stranger things have happened)
I don’t know the differences, but the Atlas decoder manual states:
“As substitutes for the no longer available #342, Atlas recommends either the NCE DA-SR or the TCS A4X. Both of these decoders are drop-in replacements for the #342 decoder, and both the DA-SR decoder and the A4X decoders have many more features than the #342 decoder had.”
And I would opt for the TCS A4X for the better motor control.
Tom
The original Atlas decoder was before the era of “silent” decoders so it does make a kind of whining noise, as many c.2000 decoders did. On mine it’s worked fine as far as power and lighting, but there are many better sound and non-sound decoders available now.
BTW I’m not clear if the OP tried it on DC? If the engines been sitting in a box for 20 years, it might not want to start and could need relubrication an a good run in period - even if the decoder eventually gets changed.
OP says both engines run fine on DC with the jumper set in analog position.
Thanks for this.
If I do replace the decoder I’d like to go ahead and add sound.
Is there a drop in replacement decoder that has sound?
I have the power cab. I currently have 2 layouts, one with the NCE power cab, and another layout with an MRC prodigy express. The NCE is on a small 4x8 layout, I recently bought a larger layout that came with and was already wired up for the MRC. I plan on removing the NCE from the smaller layout and selling that layout, and replacing the MRC with the NCE when I get time.
The NCE controller and layout it is connected to does not have a programming track, and from what I understand the NCE power cab requires a seperate adapter for a programming track that I don’t have and seems to be on backorder everywhere right now. Howeve in the past I’ve sucessfully programmed decoders with either the “program on the main” or “program on programming track” options anywhere on the “main” of that layout.
The MRC controller and layout it is connected to does have a seperate programming track and I’ve tried programming these Atlas units on both the main and programming track with no results.
I do not know what is the "current best’’ for a sound decoder. I have used TCS WOW sound decoders in many Atlas Locos. You will also want to ask here about what speaker will fit and is needed for the sound.
I need to look at what I used speaker wise and how/where the location of the speaker is.
OP, you might want to use a different word then (decoder) after the letters MRC in the third paragraph of your upper post.