TTS Decoder Problems

[sg43]

I am fairly new to DCC and am having some problems with TTS decoders.

I had to purchase 2 A4 decoders before getting Mallard to work properly, so thought I would buy a TTS fitted loco to ensure I wasn't the cause of the problem. I managed to find Maude R3600TTS and King Richard II R3370TTS. Maude works fine and happily goes round the track, but the King Richard just makes noise and doesn't move. 

Just wondering if there are reliability problems with TTS decoders or whether I've been unlucky. I have a Select controller running version 2.0. I get a 20 followed by a 30 on start up. I've read that the Select Controller is limited in what it can do, but I'm assuming that if 2 of my locos work fine it isn't a problem with the controller or my track layout.

Anyone else had similar issues?

[Chrissaf]

Just wondering if there are reliability problems with TTS decoders or whether I've been unlucky.

 

Based upon the number of posts and consistently common issues that get reported. Then it is my assessment that based upon the content of posts raised on this forum that TTS decoders do indeed have a reliability issue. There also seems to be a lack of effective quality control because many raised 'I have a TTS issue' posts relate to brand new purchases.

 

I have a Select controller running version 2.0.......... I've read that the Select Controller is limited in what it can do.

 

You have the latest version 2.0 firmware. This firmware provides a much higher amount of capability compared to pre 1.6 firmware. About the only thing that 1.6 and version 2.0 can't do is read the value of a CV and write to a CV number higher than CV255. The ability to read a CV value would be a 'nice to have' but is not particularly limiting in the overall scheme of things.

 

TIP: As a newbie poster on the forum, just be aware that the 'Blue Button with the White Arrow' is not a 'Reply to this post' button. If you want to reply to any of the posts, scroll down and write your reply in the reply text box at the bottom of the page and click the Green 'Reply' button.

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See also – further TIPs on how to get the best user experience from this forum.

https://www.hornby.com/uk-en/forum/tips-on-using-the-forum/

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[5Dublo2]

I must admit I have struggled - some have not worked at all, then the one I put in my Black Five worked but now does not. The one in my A4 works for 5 minutes and then refuses to move (sometimes with background sound on sometimes off) and also won't take any further sound commands. However take the A4 off the track for 30minutes and it will then work again for 5 minutes (which I suspect means an overheating issue) - I might try a more expensive, 3rd party decoder but am also consdering not bothering with sound as no issues with the basic DCC(non-sound) decoders

 

[96RAF]

Given the wide range of TTS loco types available and the likely minimum order of quantity per variant then there must be in the high tens of thousands of these decoders out there and we hear of just a tiny proportion of those reported as faulty. We also know TTS decoders are based on the reliable R8249 decoder hardware so any problems re more likely to be exclusively on the sound side, which is not what we are seeing reported, once the speaker is eliminated most problems seem to be loco control related. We have similarly seen low percentile problems reported against RM versus the estimated number of registered RM users.

 The only way to prove if it really is a decoder problem is to employ basic fault diagnosis to eliminate either the loco installation, the control.er or the layout.

 If you can it is better to check the decoder in a test rig such as the ESU device, although there are cheaper test rig clones to be found. This will take the loco and the layout out of the loop.

I appreciate few folk will have access to these but is the fault apparent if you use a different controller or run the loco on another layout. This will take the controller and/or layout out of the loop.

Does the fault appy only when installed in a particular loco, or does the fault follow if you install the decoder in another loco. This again takes the loco out of the loop.

Is the fault apparent only in combination with other locos on track. There have been reports of operating one loco causes others to react.

Is there a particular long or short address that gives trouble. There have been cases reported where certain controllers do not seem to want to use certsin addresses.

One commonly reported casue of failure is overheating, so does the decoder have adequate ventilation.

I could go on itemising every possible scenario, but fault finding relies upon the modeller having some basic skills and diagnostic nouse.

If you cannot achieve a satisfactory conclusion by diagnostics then by all means contact Hornby Support and/or invoke the no-quibble TTS warranty.

[ColinB]

When I first started with DCC, I had a load of issues with TTS, but more recently not so many. Firstly TTS is like bone china, very delicate, I worked in electronics for a very long time and never encountered such delicate electronics. Firstly there is a heat transfer issue, so if you cover it in heat shrink or basically anything, come your next hot day and it will probably fail. So if you can, just insulate the underneath, the thermal sensistive components are on the top. Otherwise put sleeve round it but make it loose so air can pass over it. Be ever so careful with the speaker connections, if they short it is bye, bye decoder. I cannot understand why factory fitted locos fail, surely Hornby can get it right, although I must admit when I look at the way they mount the speaker, I am always surprised, as it doesn't seem a good fit. I have a lot of them, they are a cheap source of sound and as long as you are careful they are good for the price. I think one of the issues is Hornby have used components that are very near their maximum current limit, so if there is any issue with the loco you have issues. I had the whole of the valve train jam on a Zimo based sound loco and once I had fixed the valve gear it worked perfectly, I suspect that if that was TTS it probably would have died. There again the TTS is a third of the price of a Zimo or LokSound, though I do suspect if Hornby were to up the price, I definitely would think twice about buying them.

What I also did was buy a cheap LaisDCC decoder tester (the DCC snobs moan about them, but they work perfectly well) to test the TTS decoders before I fit them, it seems to resolved most issues. Quite often it is the DCC socket in the loco is the issue, the sockets are not very good.

[96RAF]

As usual Colin the LiaisDCC tester is a blatant knock-off of the ESU product, but it is a tenner cheaper.

I know the argument is that when you invent wheels they all tend to be round.

[ColinB]

@RAF96 I suppose it is, but there again if it was an extra £10.00 I would have been less likely to buy it. Designing a Tester is not rocket science, I gather Chrissaf has one he made himself, it is laying out the pcb that is the pain which I assume even LaisDCC had to do. I could have probably made one from veroboard but it would not be as nice and probably not so reliable. I don't know if this is what happen but generally they get copied when production gets "outsourced" to China. So in those cases I have very little sympathy. I do know that the DCC socket that bwtechnologies are selling at the moment is an idea I suggested to them about a year ago, I was just happy they took their suggestion. 

[Chrissaf]

I gather Chrissaf has one he made himself

 

No not me ... mine is a commercially purchased ESU 53900 one.

 

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[96RAF]

The LiaisDCC PCB design is slightly different to the various ESU designs over the years and it is obviously printed with their own logo, etc, but to use the same tie-wrap motor securing method is a bit blatant. Getting your bespoke PCB design made is not that expensive and many firms will even populate the board with SMD devices for you, leaving you to mount the rest of the bits, like on the test rig the motor and speaker and maybe the various sockets. There are several PCB design software packages available, some a free, like Fritzing.

I made a basic vero-board tester years ago and there is a How-To on my website articles page, but I got to the stage of needing more than one and now I have mine and three others on the test board along with a LokProgrammer. Definitely very usefull tools to have available.

 

Anyhow we have drifted off topic long enough waiting for the OP to report back on if our comments have been of any help with their problem.

[ColinB]

I must admit the latest batch of TTS decoders have been quite reliable, since I started to worry about the heat transfer. I did have an HST fail during a hot day, but I am putting that down to it driving a 5 pole ringfield and it being covered in heat shrink. The other one didn't have sound, sent it back to Hornby, got a new one and only recently noticed that the sound is very badly distorted, so it is going back. The rest to be honest are usually my fault usually they seem to fail when trying to squeeze them in a small space. The last one was a Class 37 one where I was using a 21 pin to 8 pin converter in a Bachmann. I knew the space was tight but as I screwed it together the decoder just failed, I just assumed it touched something. I have had lots of issues with the sockets, on lots of the sound decoders, not only Hornby they seem to use thinner pins so quite often a standard decoder or DC header will work whereas a sound decoder will not. This coupled with the Production process seeming to damage some of the sockets, so perhaps that is the issue with a lot of factory fitted ones.

[96RAF]

The exception that proves TTS work anywhere. Shrink wrapped and stuffed in the coal bunker.

 

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[Howbi]

I have recently fitted a TTS in a new Bachmann class 37 and to overcome the restricted height above the PCB I wired the TTS to a 21pin breakout board as available from Strathpeffer Junction..........all works well............HB

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[ColinB]

@Howbiman, yes, that is exactly what I did in the end. I used the one from bwtechnical but it is the same idea. I am still waiting for the one from Strathpeller Junction to arrive (they don't Ship as quickly as bwtechnical).

[ColinB]

@RAF96 my shrink wrapped one on the HST worked perfectly for six months, until that really hot day, so who knows. It actually failed while it was running round the track. I am just super careful now.  Mind you I was fitting a LokSound for somebody when it failed, "I thought what did I do wrong ?" until the person I was fitting for said it happens a lot, so it appears they all have issues.

[Mikey1707822023]

Me too. I bought a TTS sound equipped Mallard. It worked perfectly forwards and all sounds worked. As soon as I change direction, everything stops and the loco becomes unresponsive. If I turn the power off for a while, I can use it again until I change direction. On one occasion, it started in reverse ok but then stopped when I changed direction. Today I received a TTS Flying Scotsman and it has exactly the same problem. I bought two Hornby sound decoders and installed them in a Class 47 and 66 respectively and they both work normally.

I reset the controller (Select v1.5) but no difference.

I wrote to technical support at Hornby who said they are not actioning emails for two weeks because of COVID-19, so it looks like I am returning them both for a refund. I came out of retirement after 35 years in the NHS as a nurse for a care home group where over 60% got infections and I answered all my support emails on the same day however many I recieved. There was 185 care homes. I guess that's the difference between caring and profit making. 

To make matters worse, I only found out today that Hornby cancelled my Capt Tom order I placed with Hornby months ago. I wrote to them several times and was told the delay was due to quality control issues. It's the last time I pre-order anything from them. They didn't give me the courtesy of informing me.

[ColinB]

@ArmyMedic no that is Hornby, I have two TTS decoders to go back, they gave me return numbers and told me to wait. One of them I have been waiting for about four months. I know the Hornby lovers will moan at me, but it is not typical for a profit making firm, I worked for one for 30+ years, even though trading conditions at present are difficult. I returned a failed sound decoder to another firm and it got turned round within two weeks. I think Hornby had lots of issues even before the pandemic..

[96RAF]

You say they work OK in one direction, but fail when switched to the other direction. Do you mean loss of motor control only or complete failure as in sound loss also.

 

Loss of directional motor control is a classic decoder H-bridge motor driver failing on either directional path.

 

There was a known (long since fixed) bug whereby a batch of TTS decoders would only program or operate in one direction, but this was actually track oriented i.e. if you physically turned the loco round on track or the feeder wires were reversed all was then well. This defies logic as the DCC signal is bi-polar and should not be seen any different by the decoder regardless of phasing. Worth swapping the feeder wires over at the controller just to prove the fault is elsewhere though. 

 

Complete failure of a TTS decoder in a single direction is unusual I.e. motor control and sound.

[ColinB]

I have to admit as of late all the TTS decoders I have bought work perfectly ok. That is not to say tomorrow when I run one, it will not fail. Trouble is Hornby needs to sort its QA out so none of the sockets get miswired. I know on a Hornby Schools class loco it blew up a Zimo sound unit in one direction, later found to be a mis wire on the 8 pin socket. I now check the socket with a multimeter before I fit any DCC decoders, but not everyone is like me. The two I have for return, one failed after 6 months, the other the sound is very badly distorted. Trouble is some, that people complain about, are factory fit ones, so that is not a case of bad customer fitment. Is it just the 1% failure and the 99% good ones we never hear about, or is there a fundamental issue?

[Mikey1707822023]

 

Thanks for taking the time to comment. Everything goes when I change direction except the engine sound if that was already on. The Mallard worked when I turned it around but then wouldn't go the other way. I don't want locomotives that only go in one direction whether the wires are one way around or the other. The decoders are not fit for purpose. They are going back and I don't want any more TTS sound locomotives from Hornby. Two at the same time with the same problem is too much of a coincidence.  

I opened a Hornby 8 pin docoder today and one wire wasn't soldered at all and doesn't look like it ever was. So much for quality control at Hornby. 

[Rog RJ]

@ ArmyMedic

 

"I opened a Hornby 8 pin docoder today and one wire wasn't soldered at all and doesn't look like it ever was"

 

Not the purple wire, was it?  😆

[Chrissaf]

I opened a Hornby 8 pin docoder today and one wire wasn't soldered at all and doesn't look like it ever was. So much for quality control at Hornby.

 

@ArmyMedic

Just to add to Rog (RJ)s cryptic reply.

The Hornby R8249 [as do many other brands] has 9 wires connected on the decoder, but there is only 'as standard' an 8 way connector plug. This means that one wire [the purple / mauve one] has to be free and un-terminated as there is no connector pin spare for it. This wire is the fourth function wire and is switched negative by sending an F2 command from the controller. The wire can be used for any suitable use within the loco. For example a Cab Light.

 The other three functions are Function 1 & Function 2 which are the 'Directional Lighting' functions controlled by F0 on the controller. The third function is the decoder 'Green' wire [Pin 3] on the 8 way connector and controlled by sending F1 from the controller.

Therefore it is not a 'Quality Control' issue. The decoder is designed that way and they are all the same.

Note: None of this information is applicable to the TTS decoder to which the original post relates. It is only applicable to four function 8 pin decoders such as the Hornby R8249.

[96RAF]

@armymedic

As suspected it seems like an H-bridge half failure. Send them back under the no-quibble TTS warranty.

 As Colin said we only hear about the few duff ones, not the tens of thousands of good 'uns.

[Mikey1707822023]

Cryptic isn't the word I'd use but thanks for your explanation but it wasn't the mauve wire. I have managed to the solder the culprit back on and it works ok fortunately. I bought three 8 pin decoders.

I have decided to ditch the Hornby Select in favour of the NCE Power Cab. The reviews from other modellers were good. I doubt I will ever have a huge layout, so it should last me a while. The locomotives are going back for a refund.

[Yelrow]

Use it as a Walkabout, and buy an Elite.

[ColinB]

I had an interesting one today. My Duke of Gloucester that I bought new  two years ago came with sound fitted, I decided to run it. It runs for about one loop and then the sound stops, intially after about another loop it stopped but it seems to have stopped doing that after I played around with everything. It comes back with a reset. So I rewired the socket and a fitted new socket  and changed everything, except the motor. Still it does it. Even if I put one of my spare TTS decoders in it, the same happens. I eventually fitted the decoder to a diesel and it works perfectly. So the only thing left is the motor. All the pickups are perfect, what I will do tomorrow is swap the tender with another Cornation class loco. Obviously, there is something with this loco does not like TTS decoders. Oh and I checked for capacitors and inductors, not even any around the motor. I even changed DCC controllers and it still happens. I have my suspicions what it is, but at the moment it is guess work.