Troubleshooting:- Loco that creeps forward of its own accord after resetting CV 8 to 8

[candishtowers]

I have installed 2 x 8 pin decoders into locos successfully, however I have one that keeps giving the "unable to load sound profile" etc. Numerous resets have done no good so using my ECOS controller I changed CV8 to 8, I guessed this would again reset the decoder to default values. Trouble is after I install sound profile (sound profile still will not load though) the loco now creeps forward of its own accord very slowly and although it shows up as being able to be controled by Bluetooth, I am unable to move the loco. The same is true of when I try the ECOS -nothing happens apart from the loco creeping forward very slowly. Is the decoder faulty do you think or is there a way round the problem?

[96RAF]

Take a look at the troubleshooting guide.

[BritInVanCA]

Just to add to 96RAFs comment. It may seem that the trouble shooting guide is focused on issues with sound profiles. However I've found that reloading the profiles or starting with the smallest profile (08) solves other non-sound related issues as well like getting functioning sound but no movement. Power cycling multiple times with a good gap between the outage is also sometimes effective

[96RAF]

The main problem appears to be data loss and as reported elsewhere there are two distinct stages:

1. fetching the files over the internet from the Hornby server into the app
2. loading those files from the app by Bluetooth onto the decoder.

Double error checking could be a way to find out where if any data loss occurs but this adds time to the process and of course doesn’t rule out if the problem lies at the internet or Bluetooth stage or if the fault lies within the actual profile files. This is all being worked on, but one thing is for sure, once a bombproof procedure has been established then it will become a one button press in the app to load these files.

[ColinB]

I would imagine fetching files over the internet from the Hornby server into the app should be a pretty tried and trusted method, people have been doing that for a long time.

The Bluetooth app is probably the culprit, there you are dealing with a flash memory reprogramming which is always problematic. Now here is a question for 96RAF, do they use an open or closed loop download. Open loop is where they just transfer a number of bytes, wait a time period, then transfer some more bytes. Closed loop is where the host (Bluetooth device) transfers a number of bytes, waits for the target to respond that it has programmed the number of bytes correctly, before the host downloads the next bytes. I know from experience the Elite reprogramming uses open loop as it is dependant on a user input delay function. The trouble is flash memory programming, which is what you are doing does not always take the same time.

Anyway just a thought.

[Fishmanoz]

Colin, whatever they are using, it will have been done quite independently as H&M and HRMS are completely separate organisations. It won’t be a case of the same process from the one development team.

Not that this solves the problem.

[96RAF]

Open or closed loop - Not a question I know the answer to Colin but I could ask a man who does.

[candishtowers]

Thanks for all the replies. Alas! I have tried all the Troubleshhoting methods, still the same, so I have been in touch with Hornby and I am sending the decoder back for them to examine.

[WilliamDavid]

I have found downloading the sound files is best achieved on a dedicated track.

[Fishmanoz]

As have many others, explaining why this is the current advice.