How can I unlock a decoder if I can't read?

Model Railroader Layouts and layout building
1

I’ve got two locomotives whose Digitrax decoders appear to have come, out-of-the-box, in the “Locked” state as described in http://www.nmra.org/standards/DCC/WGpublic/0305051/0305051.html.

Two locos:
Proto1K C-Liner, with Digitrax DH-123 hard-wired in (this is the second of two equipped like this, no problems with the first)
Kato AC4400, with Digitrax SDH104K1A+FN04K1 Combo

Symptoms:
Both will respond to programming, in that they move for each programming command sent. However, I can’t actually CHANGE any of the CVs. For example, if I try to program in a new address, they each only still respond to “3”.

Unfortunately, according to the topic listed above, the way to unlock them is to follow some steps to read through the eight possible CV values for CV#16. Unfortunately, I’ve got the Digitrax DB150 booster/command station, which doesn’t have read capabilities.

I tried programming CV15 with the eight possible values, 0 through 7, followed by programming a 4-digit address, to no avail. I’ve also tried resetting (CV8 = 8), although the topic listed above expressly states that the decoder shouldn’t respond to this unless CV15=CV16.

Any suggestions?

Thanks,

Brian Pickering

2

Have you got a friendly LHS or another DCC user nearby? How about a train club in your area?

3

What type of DCC system are you using? If you are trying to change to a long address, you must also change CV29 in order for your system to recognize the new address, and some systems do not automatically change it.

4

I’m not familiar with Digitrax decoders, but I’ve got several other makes and models. All the ones I’ve seen can be RESET, usually by setting one particular CV to one particular value, whether you can read it or not. A successful reset will also unlock the decoder. When in doubt, check the instructions.

5

Talk to Paul over at Northend trains on Lake city way. Hes there on Thur. eves and Sat. The owner is good at that stuff too.

6

I unlocked a stubborn decoder today that a friend brought to me. It was also Digitrax and he said it had a 4 digit address. Following the instructions that came with my system, I cleared the old address and installed a new 2 digit address of 03. I use a Bachmann EZ Command system. If that can unlock and clear it, any good system can. Somethings not being done properly.

7

I didn’t think DH-123’s were capable of locking. That’s a 5 year-old decoder…