Digitrax

[LGBfan17]

I just got my RS-3 back from the DCC installer with a Digitrax DZ143 in it and the loco runs perfectly even after I re-prorgammed it.  The installer tested the decoder at his shop before I picked it up.

[WTierce1]

Sorry for no updates. I am using the DH123 so Jim, you put the DH125 while I am almost positve that I put the type somewhere but sorry if I didn't. I put the one good decoader in my Thomas and it works fine. I don't know why the first one burnt up. I cut the plastic off of it and a tiny rectangular piece was burnt up. That is all that was wrong but I don't know how to fix it.

[Jim Banner]

Many of the tiny pieces are resistors.  When one burns up, it is usually a result of a failure within one of the integrated circuits (slightly larger pieces with many connections.)  Replacing a surface mount IC is virtually impossible without special equipment.  Even finding a replacement is difficult to impossible.  It is the price we pay for miniaturization.  Fortunately, for what we get, the price of a new decoder is not very high.

Jim

[WTierce1]

Thanks

[BradKT]

I had one or two Digitrax DCC decoders fry on me, but I thought that that was just me and my mistake.  After what I am reading now, maybe not.

I am curious.  If not a Digitrax DCC decoder for an old Athearn engine, what would any of  you recommend?  Would this other DCC decoder fit the Athearn harness made by Digratrax?  Would it be the NMRA 9 pin plug that you could just plug into the Digitrax harness?

[glennk28]

I had an unusual case of "letting the smoke out of adecoder.  Yes--it was a Digitrax, and yes, they replaced it.

I had installed the decoder in an old (1964) Max Gray HO SP 4-8-2.  I had replaced the motor with a Sagami 2032 whose current rating was well within that of the decoder. Due to limited space in the boiler I had used an N-scale decoder.  I was running it on our club layout  for quite a while when suddenly the smoke leaked out.  In order to make a neat job, I had given the decoder a couple of twists to keep all the wires together Apparently the wires were too light for the job, as they heated up until the power wires melted thru their insulation and shorted out.
gj

[WTierce1]

Mine smoked to. So you think they'll replace it?

[Bucksco]

Maybe the Digitrax website is the best place to discuss their products......

[glennk28]

Ordinarily, yes--but the circumstances in this case  could probably happen to any brand--the combination of light gauge wires, twisted, overheating and melting the insulation crerating a short circuit  gj

[Jim Banner]

My experience with a variety of different brands of decoders is that decoders fry for three reasons:
(1) improper installation, either a motor that was not isolated properly or the installer failed to properly measure the current requirements of the locomotive.  A stall test on each and every locomotive is a must, and keep in mind that the required current rating is the total of motor current AND function currents.
(2) failure of a locomotive component outside the decoder.  This can include a motor that fails and suddenly draws excessive current or a motor that was faulty right from the factory.  Occasionally, when a light bulb fails, it shorts instead of going to an open circuit.  This will almost always cause an immediate decoder failure.  And wiring, particularly wiring insulated with tape instead of shrink tubing, may short and many of those shorts can fry a decoder.
(3) a component or assembly failure inside the decoder itself.  I routinely test new decoders on a decoder tester I built years ago out of a small gear motor and a bunch of grain-of-wheat bulbs.  Very rarely have I found a decoder that was defective as received.  Interestingly, I have never had a company question a returned decoder when I tell them it was tested on my tester before installation.

I don't mean to discourage anyone from installing their own decoders.  Even if you fry the occasional one, it is still cheaper than having them installed.  And if you follow good working practices, including appropriate testing, your failure rate should drop to near zero.

Jim 

[WTierce1]

Sorry Yardmaster. The thing is is that this is the only forum account I have and honestly don't want to create another just for that.