TrainNumpty Posted February 2, 2020 Share Posted February 2, 2020 I have purchased a Hitachi Class 395 Southeastern R2821, previously unused. Driving forward is fine but backwards Stutters very badly. I believe it is DCC ready and I have an analogue layout with Guagemaster power controllers.Also on inspection there is purple wire with one end not connected to anything.Any advice please. Link to comment Share on other sites More sharing options...
Going Spare Posted February 2, 2020 Share Posted February 2, 2020 Are you sure it is R2821 and not R2821X with a DCC decoder fitted?GS Link to comment Share on other sites More sharing options...
Chrissaf Posted February 2, 2020 Share Posted February 2, 2020 The purple wire sounds like the fourth function wire used on a Hornby R8249 decoder. On a R8249 the purple wire is only terminated on the decoder itself and is hanging free at the other end..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..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/. Link to comment Share on other sites More sharing options...
TrainNumpty Posted February 2, 2020 Author Share Posted February 2, 2020 Hi Chris no decoder on this one, DCC ready, putting it in reverse the red tail lights come on and the front white lights flash. Link to comment Share on other sites More sharing options...
Going Spare Posted February 3, 2020 Share Posted February 3, 2020 The purple wire and stuttering in one direction to me are indicators that a decoder is fitted, You say the unit was purchased 'unused': was that from a retailer as new or from some secondhand source? GS Link to comment Share on other sites More sharing options...
96RAF Posted February 3, 2020 Share Posted February 3, 2020 If you have had the top off to tell us about the purple wire then how about a picture of it. DCC ready locos have a small plug inserted directly into the socket. A purple wire indicates as others have said a decoder is plugged in via a harness. The fact you are talking about red and white lights indicates the later DCC Ready model not the Blue Rapier which was definitely analogue. The earlier model had blacked out windows, the later model see through with interior detail. This may help - earlier model though.http://www.halton96th.org.uk/article9.html Link to comment Share on other sites More sharing options...
Chrissaf Posted February 3, 2020 Share Posted February 3, 2020 Hi Chris no decoder on this one,.You yourself are calling yourself a "train numpty" plus you put the line "I believe it is DCC ready". Neither of which instils us with confidence that you would recognise a decoder when fitted. All the evidence that you have provided in text so far is biased towards a decoder being fitted..Provide a photo of the internals as Rob above suggests and let the 'experts' decide. See TIP 8 in my TIPs page (link in my first reply) on how to post an image.. Link to comment Share on other sites More sharing options...
ellocoloco Posted February 3, 2020 Share Posted February 3, 2020 @TrainNumpty It sound like you have a pick up problem. I have posted about similar issues previously! You need to identify and fix where your loose wire originated from. The service sheets doesn't indicate it has conductive couplings so the issues is in the power car. Check that the pick up wires are intact and connected at the bogies - this is where they are likely to fail as they have the strain of movement. If you do find the break a spot of solder should fix it. (The two models that I have had broken pick up wires on, both stuttered and lights flickered) DCC ready or not shouldn't make any difference - if it goes one way on DC, it should go the other! If you can't find where the broken wire came from or you do, but the problem isn't fixed, please post a picture as suggested above. Link to comment Share on other sites More sharing options...
Going Spare Posted February 3, 2020 Share Posted February 3, 2020 Ellocoloco - I don't agree with your comment "if it goes one way on DC, it should go the other". I don't profess to know why but I do recall locos fitted with decoders running normally in one direction under DC control but being extremely erratic going in the opposite direction.No doubt Chrissaf has an explanation.Also, the visible wire being coloured purple is unlikely to be part of the vehicle wiring, normally just black.GS Link to comment Share on other sites More sharing options...
Souty Train Guy Posted February 3, 2020 Share Posted February 3, 2020 If it turns out this locomotive has been used, it is possible that the previous owner ran it only in one direction, causing the motor brushes to wear to the point in the other direction running will be poor (That's only if this train is used).An easy way to tell if a loco has been run is to check the pickups - if dirty, the train has been run before Link to comment Share on other sites More sharing options...
Going Spare Posted February 3, 2020 Share Posted February 3, 2020 Apologies to Ellocoloco - I have just reread your post and realise you were referring to DCC-Ready rather than DCC-fitted.GS Link to comment Share on other sites More sharing options...
Chrissaf Posted February 3, 2020 Share Posted February 3, 2020 No doubt Chrissaf has an explanation..Not really, but just purely on a totally theoretical based deduction. One scenario where a DCC decoder could have different observed actions between going forward and going backward is in the H bridge output motor control circuit on the decoder..Put simply the output motor control semiconductors on the decoder are configured as an H bridge......see the much simplified schematic below:./media/tinymce_upload/990b9455c0d283fd2b24f0fdb455a626.png.Now let's say that Q1 and Q4 energised drives the motor clockwise and the loco moves forward.And let's say that Q2 and Q3 energised drives the motor anti-clockwise and the loco moves in reverse..So, if there is an intermittent connection issue with the Q2 & Q3 circuit, then it is potentially feasible for the loco to have control issues in that direction only. In reality, this is probably unlikely as the H bridge needs to be electrically balanced to work correctly. But there could be something in the main processor H bridge driver circuit that could potentially create a similar effect..In all probability, this reverse stutter issue is physical. Either in the pickups, the motor brushes or the drive gear mechanism. There have been many forum reports where the motor torque when going in reverse tries to lift the motor away from the chassis if it is not tightly connected (dependant upon motor type). The lifting of the motor then impacts on the geometry of the gears and drive train. When going forward the motor torque pushes the motor the other way to embed more firmly into the chassis mounting. One really needs to observe the loco running on a 'rolling road' with the body off to get a more accurate idea of what is causing the problem, with particular focus on the gear meshing. Link to comment Share on other sites More sharing options...
TrainNumpty Posted February 3, 2020 Author Share Posted February 3, 2020 /media/tinymce_upload/1e6f1d9d7d30f3769f79d200e0d20a27.JPG Link to comment Share on other sites More sharing options...
Going Spare Posted February 4, 2020 Share Posted February 4, 2020 Thank you Chrissaf. I have read your post several times and think I am beginning to grasp what you are saying! We will have to see what the original poster has to say when/if anything further gets reported.GS Link to comment Share on other sites More sharing options...
walkingthedog Posted February 5, 2020 Share Posted February 5, 2020 That has a decoder fitted. Link to comment Share on other sites More sharing options...
96RAF Posted February 5, 2020 Share Posted February 5, 2020 You also have a red wire trapped between the seating module and the chassis. Pull the black thing that has all the coloured wires on it out from under the pcb so we can have a better look at it, but as stated the only thing on the end will turn out to be a decoder. Download service sheet 345 and you will see item 12 which is a DCC blanking plug. In your case this has been removed and a decoder fitted in lieu. Link to comment Share on other sites More sharing options...
Chrissaf Posted February 5, 2020 Share Posted February 5, 2020 As I deduced in my original first reply. Your loco (as others have also stated) does have a decoder fitted. It is 'DCC Fitted' not 'DCC Ready'. If you replace the decoder with a DCC 8 pin 'Blanking Plate' (plug) then this may possibly fix your stuttering in reverse issue../media/tinymce_upload/e88fefab345fb24ba8e522ebe8177898.jpg.Here's one that might be suitable (albeit a little pricey). Link to comment Share on other sites More sharing options...
TrainNumpty Posted February 5, 2020 Author Share Posted February 5, 2020 Thank you for all your help everybody, very much appreciated from a novice. Link to comment Share on other sites More sharing options...
Chrissaf Posted February 6, 2020 Share Posted February 6, 2020 I have read your post several times and think I am beginning to grasp what you are saying!.Maybe this will help with your 'grasp'. For 'energise' (in the previous reply) read that as meaning 'On'. 'On' & 'Off' as in similar to an electrical switch../media/tinymce_upload/f325cd57f28357932bc93dda3977d5a3.jpg. Link to comment Share on other sites More sharing options...
Going Spare Posted February 6, 2020 Share Posted February 6, 2020 Thank you Chrissaf - the wood is indeed coming in to view through the trees!I will be interested to hear TrainNumpty's report when the decoder has been replaced by a blanking plate.I notice X6236 has a 'gubbins' on the circuit board whereas the original X9084 did not. GS Link to comment Share on other sites More sharing options...
atom3624 Posted February 6, 2020 Share Posted February 6, 2020 Do these 'train sets' have a decoder in the power AND the dummy cars? Al. Link to comment Share on other sites More sharing options...
96RAF Posted February 6, 2020 Share Posted February 6, 2020 The service sheet shows both ends have a socket - Class 395 DCC Ready version. Link to comment Share on other sites More sharing options...
Chrissaf Posted February 6, 2020 Share Posted February 6, 2020 I notice X6236 has a 'gubbins' on the circuit board whereas the original X9084 did not. .The 'gubbins' ......is an SMD 'DC Analogue' suppression capacitor (SMD - Surface Mounted Device). If the existing motor still has a capacitor across it for suppression, then the SMD one will just be in parallel with it and not really an issue. If the existing motor doesn't have its own suppression capacitor, then the SMD one will provide that function. Either way, it shouldn't make any significant difference to the operation of the loco under DC Analogue control..The main concern would be the lighting, Some (and I stress some) 'blanking plates' include a pair of diodes to generate a 'positive return' for the 'Directional Lighting' when run on DC Analogue. But if Rob's service sheet is 100% correct for this model, there is no evidence I can see to suggest that the X9084 should have diodes on it..In Hornby models, the diodes are more likely to be located on the main lighting PCB. I did search for the X9084 before posting the link for the X6236, but all the normal sources had the X9084 shown 'out of stock'. Peter's Spares did list their own brand alternative clone of the X9084, but if I recall it was more expensive than the X6236 I provided the link for. None of the images that I found for the X9084 showed any additional components on them.....capacitor or diodes. Link to comment Share on other sites More sharing options...
TrainNumpty Posted February 6, 2020 Author Share Posted February 6, 2020 Thank you guys, does this plug 'pop out' and pop in the blanking plate, or is there soldering etc involved? Link to comment Share on other sites More sharing options...
atom3624 Posted February 7, 2020 Share Posted February 7, 2020 'Gentle symmetrical levering' with a blade screwdriver if it's tight.They're normally a good tight fit, so need to be eased out, little by little - one side, the other, back to the 1st side .. then pull out straight. Replacing with the blanking plate, ensure the pins are lined up correctly, then push all the way in and ensure flat I think describes it best. Al. Link to comment Share on other sites More sharing options...
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