Digitrax Decoder problem

Model Railroader Electronics and DCC
1

I have a Digitrax silent decoder in a LifeLike GP9. It was running fine the last time I ran it. But it has been sitting on a display shelf for several years. When I went to run it today, it was dead. No lights, no movement forward or backward, no buzz or hum. Nothing. But it did read back CVs, so it was not fried.

So I reset it Programming CV 8 to a value of 008, and it came to life…sort of. It now has the headlite and backup light but extremely dim. It moves forward and backward extremely slow.

So I measured the voltages at the 8 pin plug going into the decoder. It shows 13.5 volts track power going into the decoder. But there is only.78 volts to the lights and only 3.7 volts to the motor at full throttle. There are no hot spots or burn marks to account for the low output voltages. Is this fixable or is the decoder shot?

2

Is this decoder wired in or is there a plug? Does it have little clips holding wires to a circuit board?

This could be a loose connection. You could try resoldering any connections or removing those little clips and replacing them.

Or, it could be a decoder gone bad. That happens, too. If this is something like an old Digitrax 123, just replace it.

3

Hello All,

Go directly to the source…

Before others speculate on, and obfuscate, your situation contact the Digitrax Help Desk.

You will need to open a “ticket” and briefly describe your problem.

I was having problems with the Advanced Consisting of my NCE system and Digitrax decoders, despite National Model Railroad Association (NMRA) interoperability standards.

The Digitrax technician responded quickly and told me that NCE and Digitrax DCC systems handle BEMF differently in Advanced Consists, and advised me which CV values to change to achieve optimum performance.

I also had follow-up questions that were answered quickly on the same “ticket”.

The more details you provide will help them better diagnose your problem:

  • The type of decoder. Eg. DH166PS, DZ126PS, etc.

  • What DCC system are you using; NCE Power Pro, Digitrax- -Zypher, Evolution, Duplex, NCS, Bachmann, Lentz, et al.

  • What type of programming do you use?

  • Programming On The Main?

  • A separate programming track from the command station?

  • JMRI Decoder Pro or other third-party software?

  • The manufacturer of the locomotive(s) isn’t as important but doesn’t hurt.

If the problem can’t be resolved Digitrax has a “No-Fault” warranty, which also includes out-of-warranty replacements at less than retail.

Hope this helps.

4

Thanks for the replies. I’ll see what I can do. It is a silent decoder and not a lot of money. I may just replace it with a sound decoder. I was just puzzled why it would go bad just sitting for a few years. It was working the last time I ran it.

5

Do you know which Digitrax decoder it is?

Rich

6

No I don’t. I can’t find the paperwork. I have 60 locos with DCC, most sound, a few silent. It is a Digitrax, with the 8 pins on the top of the decoder.

7

If the locomotive came DCC ready, 8 pin socket on the light board, I can recommend TCS LL8 as a drop in replacement. It’s not a sound decoder but it is very good and just replaces the lightboard, screws onto the same mounts.

Same idea as the DH165LO which also fits using the same two mounting screws and just plugs into the Lifelike socket. Difitrax recommends insulating tape under their decoder which TCS doesn’t mention, might be a thickness thing.

8

What you are describing sounds like an engine that has been added at some point to a consist, with a different engine as the lead engine, and is still in the consist. If the factory re-set you did re-set the ID to 03/0003, it shouldn’t be affected by a consist - unless you have set up a consist with an engine whose ID is 03/0003, but odd things can happen.

BTW have you tried running the engine just on DC power? If it works normally on that, you can pretty much eliminate it being a loose wire or something like that.

9

I would suggest putting it on the program track and first do a read on the short address and then on the long and see if it will read . All else fails you can reset to factory if it will read it. Often times I’ve found just reseating the decoder will help. Personally in all my Bachmann Spectrums that I switched to either tsunamis or tcs decoders I would use the digitrax to make sure the wiring was good.

10

I have seen decoders that are trouble with a reset to default.

First try and get the address set back to 3.

Then find the CV for motor speed and set VMAX up to 255.

One decoder I have, when setting back to defaults, it puts numbers in for momentum instead of zero’s.

11

Here’s a possiblity: When Europe adopted RoHS (Restriction of Hazardous Substances Directive) in 2006, Digitrax, being the only U.S. DCC manufacturer that distributed in Europe, immediately converted their production RoHS. They did have some known problems with their conversion and had issues with reliability for some of their decoders (this wasn’t unusual in other industries as well). I don’t remember if the issues were Digitrax doing something incorrectly or if it was bad supplies, it may have even been a little of both. There may have been other issues, but one I know of is the development of solder whiskers. These develop over time whether or not the device is being used.