TTS HST Dummy Car Switching off

[ronnie thommo]

Evening folks

 

I am almost certain this will have been covered but finding the issue on hundreds of threads is difficult. Apologies if this is so

 

I have fitted two Hornby TTS sound decoders to my Scotrail HST power cars

Both  start up, the lights work fine, but when they move off, the dummy sound and lights go off after about 6 ft of travel

 

Why is this happening please ?

 

Thanks

Ronnie

[Philou]

I don't know it this may help - I bought two Zimo sound chips that had been marked 'power' and 'dummy'. Both were fitted as per markings but the dummy one wouldn't work correctly. The trick was to put the 'dummy' one in the power car first, set it up (giving its number etc) and when happy, take it out and put into the dummy end and then put the 'power' one in the power car.

 

I can't recall exactly what was the problem, but if I remember correctly the dummy one needed the benefit of 'learning' the effects of the motor (probably the back-emf) as the dummy end has no motor for it to make reference.  Once 'learnt' and put back in its correct end, all was OK. The two differently numbered chips were then treated as two separate locos and made into a single consist.

 

I don't know what DCC system you have, but on mine there was just a simple command to create the consist.

 

Cheers,

 

Philip

 

PS: TTS chips need to be set up under 128 power steps, again IIRC.

[ronnie thommo]

Cheers Philou,

 

I know the TTS chips have a No 8 on the bottom, but they all do I believe .

What you have said makes perfect sense actually & you could well be on to something here.

i think I will call Hornby tomorrow and ask them about that & see if they’ve seen the issue before.

It’s going to be something simple I think, but what, is the million dollar question  ?

 

I will update the forum on what they tell me. 
 

Thanks again

Ronnie

[Philou]

I didn't have the opportunity to do two together - if the 'dummy' chip hadn't pick up the motor, because it was in the non-powered end, then the programming may not have been successful. Anyway, it was what worked for me and I was just passing it on.

 

BTW, Richard, nice videos of yours that I see from time to time.

 

Cheers,

 

Philip

[RAF96]

Does this happen in both directions and/or does ot still do it if you swap the decoders over between cars, i.e. does the fault stay with the dummy or does it follow the decoder to the other car. Could be as simple s dirty wheels or poor pickups on the dummy car.

[ronnie thommo]

Hi guys

 

I have the Guagemaster Prodigy 2 as my controller. 
RAF96, good point, someone else pointed out it could be down to dirty wheels/ pickups, so I’ve given them the treatment so to speak and they are now spotless but the issue is still there, and yes, it’s always the dummy car, not the power car, it doesn’t follow through to that. 
When  programming, I was told to program them together on the programming track with the same address. I’ve done that, also one at a time, tried that. Also swapped the decoders over. I’ve tried that. All to no avail. 
As there are no guidelines in the paperwork that comes with the decoders, I’m assuming it’s a simple fix. If there was a process to follow then surely they would have pointed this out ? 
 

Cheers

Ronnie

 

[Pete the Elaner]

Possibly related but I have a Hornby Sapphire decoder in a class 150, so a single decoder for both carriages. I chose that because of the auto run feature, so I could leave it running up & down a branch line.

It developed a fault whereby the lights turn off shortly after I turn them on. Factory resetting the decoder has made no difference. I attribute it to a decoder fault & will use it somewhere else in time.

I wondered if yours was a similar fault but because you have sound too, this is also affected?

This is the only true fault I have ever had with a Hornby decoder.

[RAF96]

If the fault does not follow the decoder then the fault must be in the dummy car. You have proven it is not the decoder or its set up by the fact the fault occurs with either decoder when installed in the power car.

 

Whether  you can program a decoder without a motor load depends upon the controller. Any Hornby controller will program a decoder in a dummy car.

 

I suspect there is a fault on the dummy car PCB which is failing after it warms up on load. We can also rule out the pickups, etc by checking if the fault occurs with the dummy car stationary. Final resort will be to return the unit under warranty, either to the retailer or by way of direct contact with Hornby Repairs (Customer Care initially).

Edited December 16, 2019 by RAF96
Typo

[Philou]

@Richard Croft I don't want to hijack the OP's thread, but I'm interested to hear what you say about doing two chips together as it seemed not possible on my ECoS as it knows if there two chips with the same address - computer says 'no' - which why I ended up doing them separately and then creating a consist. I ask as I will have some pairing to do with chips next year.

 

Coming back to the OP, it seems that it's possibly the PCB - I hope ronnie will keep us posted, as I'm curious.

 

Cheers,

 

Philip

[tarifa]

Try putting a resistance across the the motor wires.

 

Mike

[ronnie thommo]

Ok guys so this is where we’re at.

 

I’ve contacted Hornby today regarding this issue. Quite helpful to start with :-

 

Try resetting the decoders via CV 8 back to factory settings and reprogram.  No difference 

Set the sound default from 4, to 3.    No difference

Change  the decoders round. Set the powered unit first and change over into dummy unit.  No difference

Need to send the decoder back for investigation.   Already did that. Kept it 3 weeks. No fault found they said.

 

Then stroppy !

 

Where did you get it from, send it back to them.  Can’t do that. Got them from Warley, nearly a month ago, and i’ve fitted them with replacement speakers

Must be the loco’s. You need to send the loco’s back to us.  No way, it will now be the end of January before I get them back !

 

I value all your advice, but I ignored everything I believed in when I bought these, that being you get what you pay for.

Mr Leggomanbiffo wants £236 for sound decoders for the HST’s

Olivias isn’t far behind, a couple of hundred quid.

Then there’s the speakers on top, a tidy sum.

 

I paid £59 for these.

 

The observant amongst you will recall a similar thread I put on regarding a TTS Class 66 decoder fitted in which the loco runs poorly at crawling speed.

Again, I never did get the loco running right.

 

In conclusion, I’ve done with these decoders. They are cheap, and very unreliable in my opinion.

Your replies in trying to fix this problem are greatly appreciated, and thank you, however the ‘big’ boys just aren’t interested

I have replaced the decoders with normal Gaugemaster decoders and the loco’s run lovely.

Until I can afford the £200 ish required by the above sound fitting boys, it can remain silent.

 

Ronnie

[RobjUK]

1 hour ago, tarifa said:

Try putting a resistance across the the motor wires.

 

+1 for that idea, before you scrap them!

 

Add a resistance so the decoder in the dummy unit "sees" some form of load, and see if that makes it work differently. 

And/or turn off any back EMF option in that decoder - set CV10 to 0 ?

 

It could be detecting either no current or no back EMF and going in to some form of safety shutdown mode.

 

[RAF96]

For starters the TTS warranty covers faults due to finger trouble as well as user swap speaker. That is regardless of where you bought them. Your contract is with the retailer but Hornby will overwrite that requirement.

 

It makes sense for Hornby to have both the locos and the decoders in order to do a proper investigation.. I still think there is a loco fault inducing the TTS problem. 

 

I feel you are being unreasonable in not letting them attempt to sort the problem for you, yet you condemn the product.

[Dungrange]

4 minutes ago, RAF96 said:

I feel you are being unreasonable in not letting them attempt to sort the problem for you, yet you condemn the product.

 

I'm tempted to agree with you there.

 

2 hours ago, ronnie thommo said:

Change the decoders round. Set the powered unit first and change over into dummy unit.  No difference

Need to send the decoder back for investigation.   Already did that. Kept it 3 weeks. No fault found they said.

 

Must be the loco’s. You need to send the loco’s back to us.  No way, it will now be the end of January before I get them back !

 

If the problem is always the dummy power car irrespective of which decoder is fitted in it, then I think that points to there being an issue with the PCB on the dummy power car.  You therefore have a choice - send the model to Hornby to get them to look at it, or just leave it with normal Gaugemaster decoders.  That choice is up to you.  However, if there is an issue with the PCB in the dummy power car, you may also get a similar problem at a later date after you've fitted an ESU or Zimo product.  By that time, Hornby will be perfectly entitled to say that the model is outside of Warranty.  Is it really the end of the world being without a locomotive for a month?

[125_driver]

I am glad thisnisnt just me!!! ,I have a largish HST fleet, and all of them do EXACTLY as you describe, power up nicely engine screaming away then after 4 or 5 feet engine idles back despite power being increased. Incredibly annoying and totally takes away from the experience. I have several and they ALL do it, so I'm thinking a Hornby design floor.

[delticman]

Right, all this is starting to worry me as I was about to purchase a Hornby TTS Paxman Valenta pair of decoders for my blue/grey HST. I have several TTS decoders installed in locos and have never had any problems except with a Class 20 where it would only respond when placed facing one way on the track (since sorted). The idea of putting a resistance across the motor terminals in the dummy car seems to me unnessesary as when you programm the two power cars together the dummy power car would detect the motor load through the track. If anyone from Hornby is reading this thread I would appreciate their input and I hope Ronnie gets it sorted, please dont give up on TTS as they represent great value for money.

 

Geoff

[RAF96]

Mine are installed in an old ringfield motored Intercity liveried HST converted to a DVD motor and I cannot replicate this problem on a stationary test track as I don’t have a running layout at present.

 

Edit - with ref to putting a resistance across the motor wires in the dummy car. OK for programming but not a bright idea for running as it will need to be a hefty resistor which will generate a lot of heat when throttle is applied. Better to leave the motor leads isolated.

Edited December 19, 2019 by RAF96
Additional info as marked

[Ouroborus]

Seems two different things here.  The OP says the sound and lights cut out.  The other problem reported by 125driver is a return to idle 

[NFWEM57]

This is an interesting thread as I have recently converted an original R069 HST by adding new bogies, a central drive motor, DCC sound and stay alive.  I switched off some of the sounds that should only come from the lead car and programmed both decoders with the same long address, i.e. basic consist.  I used a pair of Hornby HST (Valenta) decoders on my Dynamis powered test track and found no problems.  Both cars worked fine.  Have not tried basic consist with my ECoS. 

 

Initially I did not fit stay alive circuits and had a number of problems with constant resetting on even the slightest power interruption.   Fitted small stay alive circuits to both cars. No longer any problems.  Use the blue as the +ve connection and the -ve connection is a solder connection to the decoder itself.  Plenty of YouTube videos on this but care needed.  You could also see my how to upload for the conversion on the Hornby HST conversion thread I wrote.  Just started the Lima one.

 

Hope this helps.  

Edited July 2, 2022 by NFWEM57