sharpshooter Posted November 3, 2013 Share Posted November 3, 2013 Hi folks, I have recently inherited a number of Hornby sound locos and I have three that all seem to be suffering from a similar fault with the motor cutting out. There are two Class 50 R2802XS "Valiant" and a R2803XS Class 31 Petroleum Sector which I believe are all fitted with Loksound 3.5 decoders. The problem seems to be that when power is applied, the motors will attempt to start, then make one or two revolutions before stopping, then a short pause and the motor will start again and stop and so on. If the sound is in use, this will stop at the same time as the motor then restart, presumably as a result of the current drain. There appear to be no obvious short circuits or damage to the mechanical drivetrain or bogies. I tested the Class 31 motor on DC and all appears OK and it run without any problems, so I'm guessing that the problem may lie with the PCB or decoder, but it does seem rather a coincidence that all three locos exhibit the same symptoms. I have reset all the decoders to default, to no avail and currently use a Sprog II to test the locos on a DCC Concepts rolling road which works fine for all the other locos I have tested so far. Can anyone offer any advise as to the possible cause, or what I could try next, before I resort to stripping the locos down any further. Thanks in advance Rich Link to post Share on other sites More sharing options...
corax67 Posted November 3, 2013 Share Posted November 3, 2013 The first thing I would try is cleaning the wheels & pickups - it sounds as if the loco's are not receiving current. Link to post Share on other sites More sharing options...
pipparooba Posted November 3, 2013 Share Posted November 3, 2013 Someone had a issue with a class 56 and a class 08 sound a few weeks ago try turning the sound down first and give the track and the wheels a good clean. I have a class 31 and I've taken the fan drive out as people say it stops the motor from running freely and mine is forever stuttering cheers Ian Link to post Share on other sites More sharing options...
sharpshooter Posted November 4, 2013 Author Share Posted November 4, 2013 Looks like a have a solution, as I have just tried the three locos on my Dynamis all function with no problems. I measured the track voltages and noted that the Dynamis delivers just over 17 volts to then track and the Sprog, around 16, so it would appear that this 1v loss may make all the difference for reliable sound operation......I guess dirty track, wheels and rollers will also contribute to voltage loss to the decoder. Cheers to those who replied......thankfully, I saved myself from some complex and needless loco-dismantling. Rich Link to post Share on other sites More sharing options...
RMweb Gold pheaton Posted November 4, 2013 RMweb Gold Share Posted November 4, 2013 Yes the 08 problem is a overly loud sound setting causing symptoms similar to poor current collection, and its resolved by dropping the volume..... I own all 3 types myself but have not seen this issue on the 50 or 31, my issues have been dirty wheelsets, but also bear in mind the 31 and 50 pickups connect through the axle spigots on the ends the axle rather then through wipers ALA class 56/60 if the pockets these spigots go into get any dirt in and you can bet your bottom dollar they do get full of grease and its going no where fast! This is another example of Hornby re-inventing the wheel and over-engineering something so simple that's worked perfectly for the last 20 years! Drop the volume but if this doesn't help dismantle the bogies (carefully) the side frames are a "sod" to get off the bogie frame and flood them with IPA. Link to post Share on other sites More sharing options...
tractor_37260 Posted November 5, 2013 Share Posted November 5, 2013 Hi folks, I have recently inherited a number of Hornby sound locos and I have three that all seem to be suffering from a similar fault with the motor cutting out. There are two Class 50 R2802XS "Valiant" and a R2803XS Class 31 Petroleum Sector which I believe are all fitted with Loksound 3.5 decoders. The problem seems to be that when power is applied, the motors will attempt to start, then make one or two revolutions before stopping, then a short pause and the motor will start again and stop and so on. If the sound is in use, this will stop at the same time as the motor then restart, presumably as a result of the current drain. There appear to be no obvious short circuits or damage to the mechanical drivetrain or bogies. I tested the Class 31 motor on DC and all appears OK and it run without any problems, so I'm guessing that the problem may lie with the PCB or decoder, but it does seem rather a coincidence that all three locos exhibit the same symptoms. I have reset all the decoders to default, to no avail and currently use a Sprog II to test the locos on a DCC Concepts rolling road which works fine for all the other locos I have tested so far. Can anyone offer any advise as to the possible cause, or what I could try next, before I resort to stripping the locos down any further. Thanks in advance Rich It's also worth checking that the transit bracket screws have not been re-fitted to the chassis bottom on the problem examples - as these can foul the flywheels and cause very poor running/stopping starting etc, as I found with a second hand Hornby Class 56 I purchased. HTH K Link to post Share on other sites More sharing options...
luke_stevens Posted November 6, 2013 Share Posted November 6, 2013 With earlier sound decoders this is not an unusual issue. The current in-rush needed to charge the capacitors in the chip is misunderstood by the controller (command station) as a short-circuit. So it briefly cuts the power to prevent damage, then reapplies the power and the cycle continues. It's not really a decoder problem, rather more a combination of the command station and the wiring. There are ways of having a resistor between the command station and the track to slow the current in-rush. I don’t use one any longer but there should be lots of info on the web. Good Luck Luke Link to post Share on other sites More sharing options...
Holmesfeldian Posted January 8, 2014 Share Posted January 8, 2014 How easy would it be to upload this recording to a chip ? It sounds mental through my Sennheisers ! Link to post Share on other sites More sharing options...
Lady_Ava_Hay Posted January 8, 2014 Share Posted January 8, 2014 Not too bad! Remember though that the recording is a sound track on YouTube and will require a great deal of editing and chopping up to be usable plus all the other sounds needed to make a good chip performance will need to be sourced and edited as well. Frequently, these sorts of recordings tend to sound all wrong once on the chip but a good starting point for all that. If you have the original video then that would be an even better starting point for a compiler. i was intrigued by the old London Tube carriage in the left background. Where was this taken? Link to post Share on other sites More sharing options...
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