Jimbo1707820979 Posted March 17, 2017 Share Posted March 17, 2017 My recently purchased pre-owned "Dulwich" was fitted with a Hornby chip by my local dealer. This is one of the earlier tender driven locos, Hornby no. R2124 made in China.Several initial attempts to run it with my Elite controller resulted in the dreaded Red Light flashing up. But I pressed on with re-railing and the Dulwich ran beautifully. This was not repeated in later attempts, incl. on the separate programming track. Short circuits every time.I could not find a Service Sheet covering this model. But closer examination of the loco and tender threw up some strange results : A. There were 2 wires (black and red) from the decoder to the coupling mechanism. Other locos I looked at only had 1 black wire. Strange, I thought. B. A shock ! The tender is a mis-match, being a Triang S4470 which the Collectors Guide tells me was released with the Schools "St. Lawrence" limited edition. Never mind, says I, the train ran very well before and looks OK. C. The small copper-coloured contacts (labelled B in the photo) seemed a bit twisted and out of position. I carefully rectified this. So it was clear that coupling up the loco and tender was causing the short circuit. Not so clear, though, how. As an experiment I pierced a piece of insulation and slipped it over the brass pin on the tender, preventing feelers B and B touching home on the tender. This "bodge up" seems to have worked, but I am not clear why !Can any of the experts please help me on this ? Maybe advising a more professional solution./media/tinymce_upload/9da599c9e22442f129ec3cb05685505c.jpg/media/tinymce_upload/4dae8bde4e932f7ea821abe4640a4a7c.jpg Link to comment Share on other sites More sharing options...
pidder Posted March 17, 2017 Share Posted March 17, 2017 I would suspect a short circuit because of having two sets of contacts at the tender/engine connection. Is it possible to reverse the connections to one of the sets of contacts ? Link to comment Share on other sites More sharing options...
96RAF Posted March 17, 2017 Share Posted March 17, 2017 @JJThose A contacts on the loco drawbar grip the post on the tender and the fingers B should be flat and press up onto the plate the tender post is mounted on, not twisted as the photo shows them. What you dont want is A and B to get near each other. Does that spring allow the brass bits to move. If not what's it for. As you have said the tender is maybe not the right one then I would check where the loco left wheels are connected to A or B and then cross check the tender left wheels match up with either the plate or post as applicable. It is possible the connections are mismatched. If so you can more easily resolder the loco ones from A vs B. Rob Link to comment Share on other sites More sharing options...
olly Posted March 17, 2017 Share Posted March 17, 2017 Can you post a picture of the tender ? That would help identify the problem Link to comment Share on other sites More sharing options...
NWR-Gordon-4 Posted March 17, 2017 Share Posted March 17, 2017 The 100,000 post! 😆 When I saw this title, I thought you where talking about actual school, but now I realise you are talking about a Schools Class! Link to comment Share on other sites More sharing options...
walkingthedog Posted March 17, 2017 Share Posted March 17, 2017 Although the tender post is mounted on the metal plate it is in fact insulated from the post. so 'A' rubs on the post and the two 'B's' rub on the plate and A mustn't touch the plate and the B's mustn't touch the post. Link to comment Share on other sites More sharing options...
96RAF Posted March 17, 2017 Share Posted March 17, 2017 Another thing to check is A is connected to the drawbar so if B contact the drawbar or the drawbar contacts the tender post plate then we have short sitution. I had a nylon washer on my Mallard post sitting between the drawbr link and the B fingers until i ditched it all in favour of four pin plug and socket. Link to comment Share on other sites More sharing options...
St1ngr4y Posted March 17, 2017 Share Posted March 17, 2017 The 100,000 post! 😆 When I saw this title, I thought you where talking about actual school, but now I realise you are talking about a Schools Class!Instead of Dulwich, it should be named St. Trinians Ray Link to comment Share on other sites More sharing options...
NWR-Gordon-4 Posted March 17, 2017 Share Posted March 17, 2017 What do you mean, St1ngr4y? Link to comment Share on other sites More sharing options...
RB51 Posted March 17, 2017 Share Posted March 17, 2017 Can we keep this thread on topic please? R- Link to comment Share on other sites More sharing options...
walkingthedog Posted March 17, 2017 Share Posted March 17, 2017 If as you say it is the incorrect tender it may be wired the opposite way to the original tender causing a short once connected. If so try swapping the black and red wire round. Try to keep on topic until the problem has been resolved. Link to comment Share on other sites More sharing options...
NWR-Gordon-4 Posted March 17, 2017 Share Posted March 17, 2017 Can we keep this thread on topic please? R- OK, I am very sorry RogerB. 😀 Link to comment Share on other sites More sharing options...
Jimbo1707820979 Posted March 18, 2017 Author Share Posted March 18, 2017 Sincere thanks, Gentlemen, for your comments and suggestions. As there are a lot of facts and possibilities I will be busy getting my head round these. I will also post a photo of the tender as requested.Rob's mention of the nylon washer on the Mallard put me in mind of the old Lucas distributor washer - wrong assembly and the car wouldn't start.My apologies for the misleading title. I omitted the 's' from 'schools' to add a little intrigue. But not to cause straying off the topic. Mea Culpa. Link to comment Share on other sites More sharing options...
walkingthedog Posted March 18, 2017 Share Posted March 18, 2017 Title looked fine to me. Hope you solve the problem. Link to comment Share on other sites More sharing options...
St1ngr4y Posted March 18, 2017 Share Posted March 18, 2017 Can we keep this thread on topic please? R-Sorry, Roger - I couldn't resist it 😀 Consider my wrist duly slapped 🤐 Ray Link to comment Share on other sites More sharing options...
Fishmanoz Posted March 18, 2017 Share Posted March 18, 2017 I think this one needs to be kept on syllabus! Jimbo, you've only been told 2 things to look at. The first and most likely I'd the twisted B contacts may be touching the post instead of the plate. Untwist them and your problem should be solved. The other possibility, if not solved by the first, is that connections may be swapped in the tender such that they end up connecting the insulated tender wheels to the uninsulated loco wheels, or vice versa. But I think the first will fix it. Link to comment Share on other sites More sharing options...
walkingthedog Posted March 18, 2017 Share Posted March 18, 2017 The two 'B' contacts should be horizontal and be bent slightly upwards and kept away from the peg. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.