# Bad Decoder?



## Stejones82 (Dec 22, 2020)

Greetings all, 

HO scale, Digitrax Zephyr DCS52 system. 

I purchased a used Atlas Masterline Silver Alco S-2 Saturday at a train show. Looked new in a box that indicated equipped with DCC ESU sound decoder. Vendor said it was part of a collection. 

Took it to a club display at the show - - ran on DC, would not run on DCC having tried addresses 03 and the cab number. Took it back to vendor and he gave me $10 back, so I kept it. 

Removed the shell - - no decoder, but an 8 pin socket with no plug/blank board/dummy. Checked the Digitrax decoder selector and happened to have the one they recommend. I bought it brand new from LHS (DZ126PS). Verified that it has a speaker installed. 

Installed the decoder - - no joy. On the programming track it gives an error message of: "No decoder ack pulse" which I believe means that the command station can see no decoder. 

The loco runs on address 00. 

Could it be a bad decoder? 

Could I suspect that it had an ESU decoder which was removed? What would that do to my installing a new one (non-sound). 

ANy other suggestions very welcome - thanks in advance. 


Steve J


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## MichaelE (Mar 7, 2018)

The locomotive doesn't care what decoder is installed. It should run on anything installed provided it is the correct pin configuration and it is a known good decoder.

I don't know what you paid for the locomotive, but ESU sound decoders are around the $90 mark without a speaker on the cheap end and go up from there. I hope you didn't take a bath on this purchase.

Remove your other (if any) locomotives and program it on the active track instead of the program track. Current is usually lower on the program track to keep from possibly frying a decoder while programming, but sometimes it's not enough for the controller to detect the decoder.


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## Stejones82 (Dec 22, 2020)

Paid $60 and the vendor returned $10 so net $50. Thanks, Michael - I'll try that.


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## mesenteria (Oct 29, 2015)

Try Ops Mode using Add "00". That's the universal address for all decoders, and if you have that address active, and go through the correct procedure for the decoder, you should get it reset. Acquire ADD '03' and see if it will blow the horn or sound the bell. If not, you have a defective decoder, or a bad speaker, a bad motor, or a bad wiring job. Runs on DC, so the motor is good. You can't get sounds out of a bad speaker, but the motor should work.


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## Stejones82 (Dec 22, 2020)

Here are some pics . . .


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## Dennis461 (Jan 5, 2018)

Stejones82 said:


> Greetings all,
> 
> HO scale, Digitrax Zephyr DCS52 system.
> ...ran on DC....
> ...


I thought there should be a jumper/plug in the 8-pin socket to run on DC.
Maybe someone hard wired it, so you cannot use the 8-pin socket?


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## J.Albert1949 (Feb 3, 2018)

The Atlas "silver" series is DC, with dcc-ready provisions. Doesn't come with "factory-installed" sound. I'll guess the dcc/sound were added by the original owner.

Looks like the "green board" on top is the factory-installed board (non-dcc). It has an 8-pin dcc connector on it. But the first owner didn't use it.

A sound-capable decoder looks to have been installed underneath it, with some connections "wired through" the green board above it.

Speaker is installed over leading truck (on the left).

You *DO NOT* want to put a dummy 8-pin plug in, I think doing so could damage the dcc board.

What's the number on the side of the cab?
Did you try running it with that number?

If that doesn't work...
Have you tried resetting it by setting CV8 to "8" ..??


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