21-pin decoder socket in Bachmann On30 2-6-6-2 - q for Bachmann

[Steve Magee]

or anybody else who knows

If you take a peek into the tender of the On30 articulated, you will see that although there is an 8 pin socket into which the standard Bachmann decoder is plugged, the 8-pin socket itself plugs into a 21-pin board. The 21-pin board has all the necessary pins and even speaker outputs marked, apparently ready to solder wires into that lead to the speaker. All fine so far, I had a QSI V7 Rev U decoder running into a MRC speaker that, with a little blutac, fitted into the speaker receptacle beautifully. Gave me many hours of flawless enjoyment.

But, noticing the 21-pin board underneath, I though I could save space (and use a smaller tender load) by installing a 21 pin sound decoder. I ordered a Zimo MX644D with custom Uintah 2-6-6-2 soundfiles and installed it. It was the easiest install I have ever done.

But (should have realised this ....)

When I powered up the NCE system, I noticed the output from the EB3 (fitted with a 15w car bulb) lit. And then I noticed that I also had the smell of fried electronics and a smoke trail leading back to the tender. Opening the tender I found that my new Zimo decoder had a large burn mark on it. It was what we know here in Oz as Wallaby Bob's Cousin. Now I can exchange the Zimo for the cost of freight, so that isnt a big issue. I am concerned that perhaps the board in the artic - which was never announced as a 21-pin board - is not configured for the 21-pin standard.

Can the Bach-man, or anybody else, help me out here? Otherwise I shall have to buy an additional 21-pin socket to 8 pin plug adaptor and hope that that solves the issue.

[railtwister]

Steve,

That's an unfortunate event. It is not unusual for the Chinese factories to make the boards or wiring different from the standards, the MDC EMD Model 40 Diesel "Critter" is the first one that comes to mind, although I have had issues with locos from P2k and Athearn as well. Sometimes it's as simple as the factory just using the wrong color wire, but the bottom line is, you just can't trust 'em, you need to at least trace the existing wires first. With a 21 pin board there's almost three times the chance for them to get it wrong! It's a shame that the decoder manufacturers will be the o9nesw to bear the cost of Bachmann's carelessness in not following the standards, but I'm sure they anticipated scenario's like this when they set up the price structure of their decoders. The reality is that it's really the customer who pays for mistakes like this. Hopefully your post will help others from having the same problem...

Bill in FL