Hi!

I wonder whether this might be "finger trouble" on my behalf or a probable defective loco.

I use Märklin Mobile Station MS2 3.55. All of a sudden my Roco 78293 SBB Ae 3/6 II #10412 would not run.

I have made movie of how it bahaves when I attempt to program it:
fig12_132_roco_78293_will_not_run_576p25.mp4 (18,091kb) downloaded 20 time(s).

This has worked earlier. I had written down that I had used loco protocol “Manual MM2” and picked it up from the data bank as 36330. I then I had saved to a loco card.

This time I also made sure that the loco was alone on the track. MS2 did not report “no response from loco”, so it is being seen in some way.

I have tried all the protocols available, and they all behave like in the movie. There is a certain amount of LED blinking, but then the loco is functionally dead.

Trying to read CV address 1 only times out, no matter which protocol I use.

I opened the loco. There are two plastic stoppers on each side, I made four tiny wooden wedges. But first disconnect that grab irons from the lower position! The stoppers are 41 mm from one end and 31 mm from the other end. All seemed fine. I disconnected the motor, and it ran beautifully from some 5V DC.

I also dissconnected the sound board and pushed it back again. Observe that there are (I think) four unused holes on one side and two on the other side, and one hole about in the middle that acts as a guide, since there is no wire there. No bad contact, since no change of behaviour.

Thanks for that advice. I actually know one with one, in town!

But still, I did try "Find loco" with the MS2, with no success. No loco! I have tried all means to remove it and then add it again.

One thing I have not tried is to remove all my 13 locos and then add them all back. I have loco cards, so it should be feasible. In case the address to this loco, or something else, is stuck. But then, this loco always has had address 7. I'd rather not..

Are you saying that you think the loco might be ok..?

By the way, when you say "My Roco operates on DCC", what does it mean? There is a flora of loco protocols on the MS2, some are lists of protocol. Which one that's chosen, how would we know? I have several other Rocos and they seem to be rather digestive of protocols. I even have the brother loco Roco 68402 which doesn't have sound, and it runs.

Finally, is it possible to remove the sound decoder? I guess this is the little board that may be unplugged? And that the driving control is in another processor, on the bottom board? Edit: I tried to remove it and the unit was totally unresponsive. Plus, it looks from the figure that for analog running there is one board, and for digital there is another. When sound is added it looks to me like both digital motor control and sound control is done on that single "sound decoder" board. In other words, that "sound decoder board" = "sound and motor decoder". I guess this is common knowledge out there(?) (It looks to me like there is s PIC-controller on that board.)

Roco Zimo decoders are set to DCC address 03 from factory. Have you set your MS2 to DCC and tried it? I don't know if the address can be changed with an MS2, but it can with a CS3. It doesn't make semse that it was fine, then began not running if you didn't accidentally do somethong odd on the controller.

Yes, I have tried DCC. It works on the other Roco locos.

I think you are right, that I accidentally did something - trying to set an address with all locos connected! It sure was an accident, I know it would hurt! But anyhow, it shouldn't have been unrecoverable, should it? That's why I only said that it had worked before. But this needs to be said! Thanks! Good point!

Agree! That's what I have done (even if that was not how this started!). I even built a switch into my M-track! Rather little prototypical, but functional! Fun aside, yes, I have always had som kind of segment where the loco is alone. It's required.

Thanks. Yes, DCC plus "all the rest", individually and in the list. For the good and bad! All permutations! Writing to CV does not work, it times out. I disconnected the motor, and as mentioned in an earlier comment: it does work. I have not tested the driver's output or scoped and logged the protocol(s). Lights will not turn off or on, as it simply doesn't obey. It hangs like in the movie.

It looks like Roco's search engine doesn't search their full data base. They certainly are there:

• 78293 AC with sound (my loco)
  
• 72293 DC with sound
  
• 72292 DC no sound
  

Yes, I have tried without the loco card, to bring it up from oblivion. Absolutely nothing helps. I agree that the most plausible explanation might be some problem in the decoder. From my experience, if there is a bootloader there, that allows the firmware to become updated, bootloading may have been entered and not been completed, and left the code or data in some kind of mess.

Maybe I should try to purchase a new decoder board, since the two years' guarantee has passed. (Aside: If I had bought it in Norway the guarantee would have been five years!) But it was hard to find, because Roco had it available and not as a yo-yo at the time.