A user on the Soundtraxx groups.io forum was having trouble performing a factory reset of a decoder he had. After trying several times using ideas from responses from other users he stated this:
Thanks all. I've used all three program modes available and powered down the program track a full 15 seconds. After the reset the decoder always shows a two digit number (author's note: locomotive address) of 255, not 3. It won't accept a different number. There is no keep alive in this one and I've disconnected the speaker capacitor.
He finally contacted Soundtraxx which gave him this reply:
The fact that the CVs are reading as 255 tells me that something is occurring that is causing excess power draw on the programming track. The way CVs are read is that the command station will read the power draw of the decoder, and essentially will play a game of 20 question with the decoder: “is CV 1 0, is CV1 1” etc… and when the decoder wants to reply yes, it induces a power draw. Now, the first value queried is 255, so the fact that it reads as 255, tells me that something besides the decoder is inducing that power draw. Do you have any lights not connected to the decoder, just getting power from the track? If so, then that could be enough power draw for the command station to see it and think it is the response. Similarly, do you have a CK (author's note: current keeper) connected? As if it is, then it may be attempting to charge on the programming track which could also induce the power draw, as such you would need to wait with the locomotive on the mainline for a couple of minutes and then switch the loco to the programming track, so that the CK is already fully charged. Also on the subject of the CK, when you program CV 8 to 8, it does not reset immediately, instead, the reset occurs the next time the decoder is powered up, and as such, if you have a CK connected you would need to wait for it to fully discharge before reapplying track power for the reset to take place.
This is a good explanation of how to handle current keepers to prevent them from interfering when trying to program a decoder . You may want to print this and put it in your "Tips & Tricks" folder.
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