Potrail2378 Posted January 17, 2021 Share Posted January 17, 2021 Hi, I have a Hornby R3395 TTS Mallard. I have had it for around two years now. Just recently, when I power down my layout, then start it up again, the Mallard seems to 'forget' what it's supposed to be doing, it just sits there, no movement, no sounds. I have to put it on the programming track from my Hornby Elite and reset it.Any ideas please? Is it an easy fix, or must I reprogramme it every time? Thanks in advance. Link to comment Share on other sites More sharing options...
96RAF Posted January 17, 2021 Share Posted January 17, 2021 When it forgets who it is, will it then respond on the default address 3.The old R8215 would do that upon power down, but TTS and R8249s should be immune. Link to comment Share on other sites More sharing options...
Chrissaf Posted January 17, 2021 Share Posted January 17, 2021 One possible explanation, is that the TTS decoder has been corrupted by a brief transient 'short circuit'. These type of shorts cause 'ringing' [oscillation] on the DCC power track voltage. This can create peak spike voltages of up to 70 volts or more, this breaks down components [particularly capacitors] in the decoder. The severity of the 'ringing' can be reduced by fitting a 'snubber' across your DCC track. I suggest that you perform a full factory reset of your TTS decoder [write 8 to CV8] before re-programming it again. If the configuration sticks, then problem solved [probably only until a short occurs again if the recommended snubber is not fitted]. If the configuration doesn't stick, then my assessment is that the decoder is probably permanently damaged. Link to comment Share on other sites More sharing options...
mjb1961 Posted January 17, 2021 Share Posted January 17, 2021 Try a 4 digit address,I'm sure I had the same problem with my TTS locos and this seemed to have worked for me. Link to comment Share on other sites More sharing options...
ColinB Posted January 17, 2021 Share Posted January 17, 2021 To me it sounds like the non volatile memory in the decoder has got corrupted, it might even be damaged. Perhaps using a 4 digit address makes it write the value in a different part of the memory so effectively fixes the issue. You have reset the decoder, so that should reset the memory. I suppose you could try it on a length of track and see if the fault is still there, that would rule out any unwanted voltage spikes on you layout. Link to comment Share on other sites More sharing options...
Potrail2378 Posted January 17, 2021 Author Share Posted January 17, 2021 OK, thanks for the suggestions, I have reset the decoder to CV 8 and it seems to be working fine now. Thanks again. Link to comment Share on other sites More sharing options...
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