ColinB

Sorry the system won't let me edit my response. I was going to add you imply that a Retailer fitted the TTS decoder, I find that a bit alarming as Chrissaf is always telling everyone to measure the "stall" current before installing a decoder, so whoever it was should know better. Mind you, I have spent several hours fixing a loco for a friend, that a so called loco repairer (he charges serious money to fix locos) had messed up and it wasn't the first one he had done this to. Moderator message - Colin, when you find the edit button not responding, reload your browser page and you should find the edit button will start working again.

I have never bought a decoder from Hornby, but I always return my broken TTS Decoders to them. You probably didn't get the no quibble guarantee that comes with it. Usually you have to tell them where you got it from with a receipt and they like the batch number on the end of the box if you have it, but I am assuming your one is near a year old so even if you had bought it off them you are very unlikely to have kept the box. The issue you will have is that it needs to have the original 8 pin connector on it. Next time find somewhere to fit an 8 pin socket. On my tender driven locos I put it in the loco with a 4 pin connector to the tender as Hornby do on their models except the other way round ( Socket in loco not tender). That is the trouble with ringfield motors the stall current is in excess of the max current limit of the TTS decoder (near about 800 mAmps), hence when it jammed it took the decoder with it. That shouldn't happen if you have the right decoder with the right current limit. I did think about putting a 500 mAmp reset-able fuse on the motor output of mine when I was having issues. In the end I just didn't use TTS decoders on motors with high stall current.

If you have a short across the motor that would explain the TTS decoder failing. They are supposedly short circuited protected but in my experience not for very long. That would explain the H bridge circuit failure. If it is a ringfield motor the current consumption is on the limit for a TTS decoder, although I did find the 5 pole variety was a lot better. Check if there is a capacitor across the motor, this could have failed.

I think the important information is in the second sentence, in that it was going well until today. It sounds like the fault is in the dummy car. Something is obviously "shorting" in there. If the unit has lights fitted then I suspect one of the diodes that drives the lights has gone short circuit, that would definitely cause issues. If if has lights in the "dummy" car try disconnecting them.

I don't know what the concern is with DCC, I use the same wire on my DCC layout as I did with my DC layout. Initially my layout was DC with isolating sections controlled by a 4 track DC controller. For DCC I just paralleled the four sets of wires together. My layout is 16 foot by 10 foot and I use 7/0.2 wire basically because it is flexible. I suppose as it initially was 4 tracks each supported by its own wiring system, then the only time you get the big currents is where I have paralleled them together where I use thicker wire. I imagine as DCC is a reasonably high frequency signal you could have to start worrying about transmission line theory, but I have not noticed any signal loss of my layout and really you don't want to go there. If I remember the limit for CAN which is a similar type of system, is 2 metres so the best idea is to feed power from a single point radially so you do get any excessively long runs of wire. The biggest issue is probably capacitance so direct wiring to the track is probably preferable.

From what you describe, it sounds like the decoder has died. Normally once you get the short you get the burning smell as the input diodes on the board just fry themselves. Recently though I had a LokSound decoder where the diodes were shorted but not drawing much power, so I was lucky and just replaced them. If it presents a short across the DCC there isn't a lot you can do as the DCC is never going to see a reset command. It sounds like it is under a year old so return it to Hornby under their no quibble guarantee. This has happened to me and to several others looking at the posts on this forum. I would really like to know what causes it. Generally as the decoder is happily installed in the loco there should be no way it should blow up unless it overheats, but listening to your symptoms it doesn't sound like you did this. The only other thing that could be causing an issue is if there is a capacitor across the motor. These have a habit of going short circuit and taking the decoder with them.

I finally sorted this, I found that by replacing the wheels with a new set that the fault disappeared. It was obviously the gear on the centre axle that was at fault. I must admit I examined the gear closely but I couldn't see any major fault. The only thing I can think is as replacement wheels for this loco are not easy to get, someone glued the gear wheel back together when it spilt, causing a slight irregularity. Looking at the gear it does look like it has been glued but I need a better magnifying glass. The other thing that was more important was I replaced the wheels with the later set that I could get. I thought I would have to mess around with the bearings but they fitted perfectly.

Great, thank you "Going Spare".

I was checking to see if the latest Cornation front bogie was available as a spare. So I looked up the appropriate Service Sheet 438B to get the part number as X6709. When I do a search on that item it lists Adams pickups with that same part number. So can someone enlighten me as to the right part number?

I must admit I have had issues with lots of decoders. In the end I found the most reliable ones, in that they run the loco properly are Hornby, Zimo and surprisingly LaisDCC. Hornby decoders have issue with old locos with high current, but generally they let you know by going bang with lots of smoke. LaisDCC seem to work reliable as long as you have a decent DCC signal (no dirty track) and for me Zimo seem to be the best, having a reasonable current limit and work well even on dirty track. I have tried Gaugemaster, Hattons and DCC concepts ones, now I am sure that they are perfectly ok but in my applications they never seem to work as well as the three I first mentioned. I have never used TCS, but normally the issue I find is there sometimes seems to be a mismatch between decoder and motor, causing the decoder to current limit.

The way I did mine, I have 3 of them in different guises, is to use a 6 pin flying socket. I found DC concepts ones are the best. I then use a 6 pin direct plugin Zimo decoder covered in heatsink as 96RAF says loosely shrunk around it. You will find this will fit on top of the motor case, I use black tack to hold it there. As to getting the body of, it is held by two plasic clips at the front of the loco, carefully prise them open using a screwdriver. Be careful as being very old they are very brittle.

Yes all mine are wired like that, but this one is different. I had a look at the 4 pin socket and it looks like it left the factory like that. I suppose I was lucky I didn't connect it to any of my other Duchess tenders. I think seeing as I am replacing the broken loco lead I will rewire to conform to the later Hornby wiring of 2 and 3 as the motor connections. This loco is eleven years old so I suspect it is one of the first with the 4 pin lead. Loksound don't support that decoder anymore, as I found out when trying to fix one before, so I have to be super careful with any of the wiring. Anyway thank you for the information, I was getting a bit worried because all the locos where I have added the 4 pin lead, I have followed that same convention of 2 and 3 as the motor.

I am repairing an old City Of Sheffield Duchess. This has a 21 pin DCC socket in the tender with I assume a LokSound decoder. Looking at the web it was supplied with this. Needless to say there were lots of issues with the loco, but I noticed that the Loco/Tender connector is wired different. The two inner wires pins 2 and 3 go to pickups, whereas pins 1 and 4 go to motor. This is the opposite to my current Hornby locos and the ones where I have added the loco/tender connection. Did Hornby originally wire it this way, because it means if you connect the tender to a more modern loco for testing you would blow up the decoder.

Looking at where it fits I figured it was the locked sort so I ordered the X8849L Idler Gear (Locked) and the X8849L/13.8 Idler Gear (Locked) Set. The X8849L/13.8 intermediate gear is too small, so the normal X8849L (locked) is the right part although the intermediate axle is wrong, on this loco there is no step. As to the loco, the original gears were correct but very "chewed up", I would have liked to have changed the gear on the wheels but that only comes with the wheels which are "out of stock", so I cleaned it up with a small jewellers screwdriver. That coupled with the crankpin sticking out the back of the wheel and the pickups interfering with the wheels were the reason it didn't run smoothly. Having fixed all that I have now found there are issues with the motor. If I could get the worm drive off I would use one of my cheap Chinese motors.

Unfortunately, when looking for small screws the only place I seem to be able to get them is from China via EBay. Sometimes if they are used on Laptops then they are also reasonably easy to get.

The Lima motor is a bit marginal for the TTS decoder, the TTS decoders maximum current is 500 mA, Lima motors can draw in excess of this. That still doesn't explain what is going on. It is as if the Select is not sending out the reverse command. I know I am always saying this, but that is why I bought a decoder tester. I assume it all worked with a normal decoder before you put the TTS decoder in. The only thing I can think of, is you have got a wire mixed up.

Does anyone know what is the correct gearset for R2782XS Hornby Duchess City of Sheffield. I found the service sheet for the loco, which it lists as X8849, but it appears from Peters Spares that there are 4 types. The loco I am fixing for someone appears to have the wrong one, but I am not sure.

I have got a Hornby R2782XS that I am trying to fix, that has got issues with the wheels not rotating freely. I have removed the motor and the wheels turns perfectly, so I suspect the gear train. Does anyone know what gears I need? I found the Service Sheet and it says I need a X8849, but when I look at Peters Spares there appears to be 4 types, locked/free moving, 13.8/11.3. Now as this loco has an issue with the gears and I don't know its history, what one should I use to replace it.

Having read a post on another "chat room" it appears that Hornby decided in that case not to supply a certain firm in Liverpool with none of a certain prerelease. So probably this is the same. Perhaps what is happening, Hornby is short of a large amount of units, being lazy they decide not to supply the Retailer with the biggest amount of orders with any, thus preserving all the other orders to the smaller retailers. Hornby then only upset one Retailer, who they consider will recover, rather than the many that had smaller orders. As I say just a theory. Of course if their new models are the same quality as their Thompson A2s, then there this won't be an issue any longer.

I have the same issue with a lot of my locos. In the case of rebuilt Merchant Navy and Battle of Britain I found there was very little space to put in a decoder, worse still a TTS decoder plus speaker. I decided to put all the DCC in the tender and connect using the 4 pin lead and PCB. Trouble is the loco and tender are permanently connected together as it is not a good idea to connect and disconnect the 4 pin plug from socket (about 10 to 20 goes for that type of connector), so yes I had to start carving the inner foam. I didn't want to do it, but it was a choice between that or eventually having to replace the plug and socket. I do the same as you, wherever possible I try and buy a proper Hornby box for any unboxed items, but people want stupid money for the boxes.

We used to do that in an engineering company I worked, they got paid 95% for delivery and 5% if the product was successful. On the more difficult projects the Supplier just took the 95% and left us with the mess.

Lets just hope that none of Hornby's products are in a container on the boat that has been en-pounded on the Suez Canal (the one that blocked it for a couple of days). Looking at the size of that fine I suspect it will be a long time before the owners of the containers get their products.

I don't know you are right or not Corky, it certainly makes a change from the normal sort of post and last time I looked "free speech" was allowed. It also is useful to know why just lately Hornby has been having lots of issues, with supply and quality. If your production is in China and there is a flight ban, then there will be issues. As for the models not running properly, if you get one of the 90% that China make properly then as I have found with many Hornby models then there is no issue. Having a large disjoint between manufacturing and production does cause issues, in that errors don't get fed back that well. If you were around in the 70's that was half the issue with BSA/Triumph going bust (making a frame where the engine didn't fit). That probably also explains the issues with Quality control, again when a company tries to save money, that is another department that usually gets cut.

Hornby moved their production years ago. I remember at the time it was quoted as cheaper production costs and people with smaller hands to put the models together. That was when they were more like toys so quality was not so much of an issue. Now they are trying to make a high precision model, with increasing production and Shipping costs in China that accepts a reject rate of 10%. Managers also neglect how much effort is required in maintaining a remote production facility and usually in any "downturn" it is the travel budget that suffers. Final result is the Thompson A2 which has numerous production faults. It will be interesting to see if quality improves on the Gresley P2 which is a "new build".

I bought the encoders for my Fleishmann off EBay, they worked perfectly ok. I think the Elite uses a slotted spindle to hold the control knob whereas the Fleishmann uses a serated spindle. They are a cheap switch that is a cheap make or break switch that gets fed by a resistors from the main board, there was a link on one of these posts as to where you can get them. We used virtually the same item in a Ford car radio. The biggest trouble is that the Elite expects an absolute perfect switch so when they get old you start to see lots of issues.