Decoder replacement for 2-6-6-2

[tmiller]

Hey guys, I have a DCC Equipped C&O® H-4 2-6-6-2 Articulated Locomotive w/Vandy VC12 Tender with a bad decoder. I want to replace it, but want to match what was installed from the factory. I am assuming it is a Soundtraxx, from what I have seen in the past in Spectrum locomotives.

Any help in identifying the decoder would be appreciated.

Thanks.

Ted

[richg]

According to the Online Product Catalog, this loco now comes with a sound module, not a sound decoder.
There is a separate non sound decoder for motor and lights.
If yours has a factory sound decoder, Bachmann does not sell them.
You will have to send the loco in for replacement or install a SoundTraxx Tsunami yourself.

Did you ask for any help here first for this loco?

Rich

[tmiller]

I not sure of the vintage of this model, but don't think it is too old.

This friend of mine bought it used, and it has a sound decoder installed, piggy backed on top of the usual DCC decoder. Right now the loco does not do anything. Somehow the sound decoder got fried and needs replaced. I did install as a temporary test, a diesel decoder, again plugged into the factory DCC decoder, and it came to life, sound and power.

Since this is a Spectrum with sound, I assumed it had a Soundtraxx. I have another Spectrum steam loco that has the Soundtraxx decoder.

Ted

[richg]

What does the defective decoder look like?

Is it a shrink wrapped decoder plugged into the PC board? Those type are installed by users. I have done some of those.

Is it a square PC board type with exposed components plugged into the PC board? Those type are factory installed. I have bought a couple of those. Bachmann does not sell those.

A photo can be a big help.

Rich

[tmiller]

Rich,

The decoder is shrink wrapped in a blue wrapper. I guess it could have been a user installed decoder, but my question would be if this sound decoder went bad, why does the engine not respond with just the PC installed board? It is listed as DCC on Board, and I do not see any mention of sound.

Ted

[tmiller]

Rich,

Just for tickles I tried the loco, without the sound decoder, again on the track. No response what so ever. If the PC on board does DCC, then why do I have nothing? The so-called sound decoder in question had to be installed for it to work, or at least that is what I think. Or did it have a non-sound decoder installed and maybe it was replaced by a sound decoder by the user?

What say ye?

Ted

[railtwister]

Rich,

Just for tickles I tried the loco, without the sound decoder, again on the track. No response what so ever. If the PC on board does DCC, then why do I have nothing? The so-called sound decoder in question had to be installed for it to work, or at least that is what I think. Or did it have a non-sound decoder installed and maybe it was replaced by a sound decoder by the user?

What say ye?

Ted

Hi Ted,

Maybe you should post a photo, since it is unclear from your description what you actually have. Most of the Soundtraxx decoders I have seen come in purple shrink wrap, while most of the blue shrink wrapped decoders I've seen are Digitrax. Digitrax does make an add-on sound board for some of their decoders. Since the loco was bought second hand, it could have anything inside.

Bill in FtL

[tmiller]

I will get a photo posted tomorrow. And yes you are correct about the purple shrink wrap on Soundtraxx decoders. I was thinking that the loco cam with sound, but I stand corrected. It just puzzles me why it won't run without the secondary decoder.

Tomorrow.

Ted

[richg]

Older SoundTraxx LC series had yellow shrink wrap. The Tsunami series has purple shrink wrap.
Bachmann non sound are usually black shrink wrapped.
The PC board is usually equipped with an eight pin socket. Plug in a DC adapter for DC only operation or a non sound or sound decoder that has an eight pin plug on it.
Bachmann usually supplies a 6 pin adapter or two three pin adapters. You can see the adapters in the Bachmann loco diagram page.
With nothing plugged in, no operation.
I have never seen a decoder with blue shrink. One person said Digitrax.
That is why a picture is worth a thousand words.

You cannot assume with DCC. There are many, many variables.

Rich

[richg]

I will get a photo posted tomorrow. And yes you are correct about the purple shrink wrap on Soundtraxx decoders. I was thinking that the loco cam with sound, but I stand corrected. It just puzzles me why it won't run without the secondary decoder.

Tomorrow.

Ted

Just in case, many use Photo Bucket to upload photos. A few have tried to upload right from their PC but it does not work.

I have to assume you have the older version loco that has the PC board for lights and motor only. That PC board has maybe four diodes, some resistors, capacitors and a couple inductors that might look like green resistors or a couple items with coiled wires on them. Labeled D, C, R, L.
A decoder would have about six to eight IC's with a lot of pins on them. The microprocessor chip would have maybe thirty to forty pins.

As I said, you need the DC adapter or a decoder.

Rich

[West Bound]

Is the sound module plugged in on top side of the electronics board or the underside of the board? If it's on the top side try plugging it in to the underside of the board. -john

[tmiller]

Okay guys, here are the pictures attached.

http://i1056.photobucket.com/albums/t367/tedm453/DSC_2678.jpg

The first one shows the PCB mounted in the tender. It has a 20 pin adapter plugged in the top of the PCB. This adapter has the standard NMRA 8 pin female plug on the other end.

http://i1056.photobucket.com/albums/t367/tedm453/DSC_2680.jpg

This is where the sound decoder plugs in as shown in the second picture.

I am wondering if this could be an MRC decoder. I have used them before, and they are shrink wrapped in an identical color.

So, probably out of the box Bachmann had a non-sound decoder plugged into the 8 pin plug, which gave it the DCC capabilites. Then someone wanted sound and replaced the non-sound factory decoder with a sound capable decoder.

Now, what say the experts.

Ted

[richg]

Very good. That does eliminate a lot of questions.
By the way, use the fourth Photo Bucket option, IMG like I said before. The photo will pop up without anyone having to click on the link you provided.

I have not seen that type of decoder before so no help here.

Rich

[nfmisso]

Hi Ted;

As noted above; if you un plug the blue shrink wrapped thing; you have to plug something into the 8 pin socket (2x4 pins) or nothing will happen.  The something can be another decoder or a dummy plug.

[West Bound]

After looking at your photos I opened up my tender to refresh my memory. I have a sound module that plugs into the main board. But the module is upside down with the capacitor bumps the bottom. This is opposite from the way the module plugs into the EM-1. I had taken the tender apart and when I put it back together I plugged the sound module in with the capacitors  facing up like the EM-1. The engine was dead. In trying to trouble shoot the problem,  I plugged the module upside down on the board and every thing ran perfect. The module is upside down due to lack of space in the upper part of the vandy tender. Why not try  plugging the adapter upside down and see what happens. - john