Phil47gwr Posted January 13, 2017 Share Posted January 13, 2017 Okay, I've managed to burn out a decoder. A Gaugemaster one so I'm guessing it's not a problem with the decoder itself. Here goes: I bought a while ago the Hornby King James I and finally got around to fitting it with a decoder. The loco runs fine on a separate DC track but when I installed a Lokdecoder 10231-01 I couldn't get any response when I tried it on my main (DCC) track. Took it to my local MR club and they couldn't get a response either. So I put the blanking plug in again and tried it on the analogue track - no problems. Thinking the decoder was faulty I put in a Gaugemaster DCC26 decoder. This time it wanted to move as soon as I put it on the track despite the controller being set to a different loco number and zero on the throttle. Accompanied by a smell of burning. Ah-ha, you've correctly guessed a short circuit. Removed the DCC26 and sure enough the decoder is toast. Put in the blanking plug again and at least the loco still works on the analogue track. I'm now hoping I haven't fried the wiring on my main DCC layout. I use Powercab so hope they have some kind of short circuit protection. Advice please. NB: I now wonder if I pushed the decoder plug in far enough. Could that be the problem? Link to post Share on other sites More sharing options...
RMweb Premium MickD Posted January 13, 2017 RMweb Premium Share Posted January 13, 2017 Hi, I have just done a search on the forum and come up with this. http://www.rmweb.co.uk/community/index.php?/topic/117683-Hornby-king-problems/ I don't know if this is your problem, but it does seem likely. A search usually points you in the right direction!!. MickD. Link to post Share on other sites More sharing options...
amdaley Posted January 13, 2017 Share Posted January 13, 2017 Okay, I've managed to burn out a decoder. A Gaugemaster one so I'm guessing it's not a problem with the decoder itself. Here goes: I bought a while ago the Hornby King James I and finally got around to fitting it with a decoder. The loco runs fine on a separate DC track but when I installed a Lokdecoder 10231-01 I couldn't get any response when I tried it on my main (DCC) track. Took it to my local MR club and they couldn't get a response either. So I put the blanking plug in again and tried it on the analogue track - no problems. Thinking the decoder was faulty I put in a Gaugemaster DCC26 decoder. This time it wanted to move as soon as I put it on the track despite the controller being set to a different loco number and zero on the throttle. Accompanied by a smell of burning. Ah-ha, you've correctly guessed a short circuit. Removed the DCC26 and sure enough the decoder is toast. Put in the blanking plug again and at least the loco still works on the analogue track. I'm now hoping I haven't fried the wiring on my main DCC layout. I use Powercab so hope they have some kind of short circuit protection. Advice please. NB: I now wonder if I pushed the decoder plug in far enough. Could that be the problem? Did you put the loco on a programming track after you fitted the decoder ? Always do this as if there is a short it will show up without destroying the decoder. Link to post Share on other sites More sharing options...
RMweb Gold RFS Posted January 13, 2017 RMweb Gold Share Posted January 13, 2017 The Lenz decoder has short circuit protection and hence will not (usually) burn out if there's a short. Not so the DCC26 I suspect. If you can read back the CV values of the Lenz on another loco have a look at CV 30, since any non-zero value there will indicate there's been a problem (eg if CV 30 = 4 then there's been a motor short). And as in the previous post, always test on the programming track first. Link to post Share on other sites More sharing options...
Stephen Freeman Posted January 13, 2017 Share Posted January 13, 2017 The Lenz decoder has short circuit protection and hence will not (usually) burn out if there's a short. Not so the DCC26 I suspect. If you can read back the CV values of the Lenz on another loco have a look at CV 30, since any non-zero value there will indicate there's been a problem (eg if CV 30 = 4 then there's been a motor short). And as in the previous post, always test on the programming track first. Hi, As far as I know NCE Powercab does not have any short circuit protection, indeed, I believe this is in the instructions along with the advice to fit protection. A Tam Valley Circuit Breaker is what Coastal DCC sell for this purpose. (at least they did 18 months ago) and it does work. Link to post Share on other sites More sharing options...
Mike Riley Posted January 13, 2017 Share Posted January 13, 2017 Hi, As far as I know NCE Powercab does not have any short circuit protection, indeed, I believe this is in the instructions along with the advice to fit protection. A Tam Valley Circuit Breaker is what Coastal DCC sell for this purpose. (at least they did 18 months ago) and it does work. If there is a short, the PowerCab will reboot and keep doing so until the short is cleared. If this happens too many time it will give a problem with the PowerCab as I found out during a spell of unusually hot weather which caused a rail break to close up. Then its back to the North Coast for it a wait a few months. Always fit a circuit breaker. I use the NCE one but others are available. Link to post Share on other sites More sharing options...
JJGraphics Posted January 13, 2017 Share Posted January 13, 2017 The Lenz decoder has short circuit protection and hence will not (usually) burn out if there's a short. Not so the DCC26 I suspect. If you can read back the CV values of the Lenz on another loco have a look at CV 30, since any non-zero value there will indicate there's been a problem (eg if CV 30 = 4 then there's been a motor short). And as in the previous post, always test on the programming track first. If you are using an ESU50200, may I suggest that you make sure the Program Track Currentless option is ticked in General Setup > Setup 2 at least for the first test. If this option is not ticked, full DCC power is applied to the Programming Track when programming is not in progress. In theory this should not be a problem as the circuit breaker in the ESU50200 is very fast to cut off the supply if a fault is detected, but it might help to save a decoder that does not have short-circuit protection if there is a wiring fault in the loco. John Link to post Share on other sites More sharing options...
Phil47gwr Posted January 13, 2017 Author Share Posted January 13, 2017 Thanks for the replies. Did you put the loco on a programming track after you fitted the decoder ? No, I didn't, I put it straight onto the layout which I've always done. Memo to self: I need to set up a DCC test track alongside the DC one I use. I will look into the circuit-breaker option and see how it's fitted. I bought the King at a Toyfair and the merchant did seem keen to be rid of it. Odd that it works okay in DC. Will do further research and respond. Link to post Share on other sites More sharing options...
RMweb Premium Vecchio Posted January 13, 2017 RMweb Premium Share Posted January 13, 2017 Just to let you know - happened to me as well. So it is not related to a certain loco as mine was a continental one from Roco. Happened on the club layout with NCE powercab. I have no idea what was the reason, the loco run before on my home set-up. But if there is a short - the NCE has no mercy - it put's power in until it smokes.... Link to post Share on other sites More sharing options...
RMweb Gold RFS Posted January 13, 2017 RMweb Gold Share Posted January 13, 2017 Thanks for the replies. No, I didn't, I put it straight onto the layout which I've always done. Memo to self: I need to set up a DCC test track alongside the DC one I use. I will look into the circuit-breaker option and see how it's fitted. I bought the King at a Toyfair and the merchant did seem keen to be rid of it. Odd that it works okay in DC. Will do further research and respond. The problem is usually the 8-pin socket. It can happen that stray solder can bond the pickup and motor connections underneath - eg 1 to 8 or 4 to 5. But that's exactly what a blanking plug does anyway hence there's no problem on DC. But when you plug in a decoder, that soldering error will short out the decoder. It's usually pretty easy to fix if you can unscrew the 8-pin socket and file away the accidental join. Link to post Share on other sites More sharing options...
Phil47gwr Posted January 13, 2017 Author Share Posted January 13, 2017 I'll have a go at that. The King is unusable on my current layout so it's fix it or put it in a glass case. Link to post Share on other sites More sharing options...
250BOB Posted January 14, 2017 Share Posted January 14, 2017 I know a lot of people buy locos at toy fairs, I have been known to do it in years gone by. However, that's the risk, have you got a receipt, have you got the traders name, address, phone number...??? Because I use shops to buy from, I have little sympathy for the bargain hunters trying to get the cheapest deal.....no offence. I do sympathise with you for your problem, but it could easily be resolved if bought reputabley.?? Link to post Share on other sites More sharing options...
RMweb Gold RFS Posted January 14, 2017 RMweb Gold Share Posted January 14, 2017 I know a lot of people buy locos at toy fairs, I have been known to do it in years gone by. However, that's the risk, have you got a receipt, have you got the traders name, address, phone number...??? Because I use shops to buy from, I have little sympathy for the bargain hunters trying to get the cheapest deal.....no offence. I do sympathise with you for your problem, but it could easily be resolved if bought reputably.?? Perhaps a little unfair on the trader, as the loco runs absolutely fine on DC. There's only a problem when you fit a decoder, and that is probably due to a manufacturing fault that it came off the production line with. One test you could try is using half the blanking plug. Put the loco on a DC track and fit the blanking plug so that it only joins the two sockets at one end. If it works this way with one end left bare, it means the two sockets at the bare end are incorrectly live to each other. Hornby are usually very sympathetic in these circumstances as the problem is a manufacturing fault. I would give them a call and explain the situation: they are likely to agree to repair the loco free of charge regardless of its age. Link to post Share on other sites More sharing options...
250BOB Posted January 14, 2017 Share Posted January 14, 2017 Ok, maybe the trader didn't know, let's give him the benefit of the doubt. My real point is buying from box shifters at toy fairs, where is your come back, where is your receipt, where are your rights etc etc Link to post Share on other sites More sharing options...
Phil47gwr Posted January 14, 2017 Author Share Posted January 14, 2017 Hi 250BOB: I understand your point but the trader (who happened to have a stall at the fair) has a shop I have visited several times and is a well-known Midlands hobby shop. They have, I understand, now ceased selling Hornby products and I may have been one of the beneficiaries of this process of offloading. I do not think it is right to name them as I don't hold them responsible - unless I find the receipt! Link to post Share on other sites More sharing options...
Phil47gwr Posted January 14, 2017 Author Share Posted January 14, 2017 Here are some pictures of the underside of the plug board in the tender. I'm not sure what to make of them. Link to post Share on other sites More sharing options...
sp1 Posted January 14, 2017 Share Posted January 14, 2017 Here are some pictures of the underside of the plug board in the tender. I'm not sure what to make of them. PlugBrd01.JPG PlugBrd02.JPG PlugBrd03.JPG That's shocking. I'm sure a blind two year old could do a better soldering job with one arm tied behind his/ her back! Link to post Share on other sites More sharing options...
RMweb Gold RFS Posted January 14, 2017 RMweb Gold Share Posted January 14, 2017 Indeed that does look a bit of a mess. There appear to be two pickups per side (red and black wires) which would tally with there being pickup wires from both tender and loco. The wires going to the motor are top left and bottom right (orange and grey), but it looks as though some of the insulation has melted and hence may be touching the pickups. So you do need to make sure the orange and grey wires are in no way touching. Seems also that the blanking plug has solder tabs for the wires, which are then connected to the pins themselves via the circuit board - presumably to aid amateur solderers! Having made quite sure there's no bad contact I'd try the Lenz decoder again but on the programming track. But if you can't get it to work I'd definitely get Hornby to fix it for you, which I'm sure they'll do without charge. Link to post Share on other sites More sharing options...
smokebox Posted January 14, 2017 Share Posted January 14, 2017 The crushed wires with the flattened insulation are a possible cause of trouble as well as what looks like poor quality soldering. The crushed wires could be making unwanted contact when the decoder socket is screwed back into position. I would reposition them before refitting the circuit board. Link to post Share on other sites More sharing options...
RAF96 Posted January 15, 2017 Share Posted January 15, 2017 I would unsolder the lot and redo them properly. What a mess from the factory. Crushing would seem to be the likely cause of the short as it would be shorting across that side those connections being motor and pickup and the first rule of dcc is isolate the motor from the pickups when fitting a decoder. A closer look shows much the same on the white wire. Link to post Share on other sites More sharing options...
RMweb Premium Izzy Posted January 15, 2017 RMweb Premium Share Posted January 15, 2017 I would agree that the soldering could be better (and I have seen worse), but having been to China and seen both the highs and lows I would not wish to pass further comment..... It would I think be beneficial to re-do it and ensure there are no shorting bridges anywhere. If you feel capable probably quicker/easier than sending back to Hornby, and at least you would know it was proper. With regard to your original post and the 'fried' Gaugemaster chip, could I suggest that after 24/48 hrs - it's probably that now - you re-try the decoder. Several of Gaugemaster decoders are/were made by Digitrax and my experience is that they are quite robust and have some thermal protection that kicks in and shuts the chip down for a while to allow them to recover when subjected to too much heat past a normal short circuit. I have certainly had this with the small 6-pin type which seem completely dead, but a day or so later work as normal with no apparent side effects. This has happened to one poor chip I had several times (!) - I use it as a guinea pig, and it still works now. Izzy Link to post Share on other sites More sharing options...
RMweb Gold The Fatadder Posted January 15, 2017 RMweb Gold Share Posted January 15, 2017 As I've mentioned on the other thread, it's also worth looking at the soldering on the loco to tender socket is every bit as bad. My first had a short on both (thankfully I was using a Lenz chip and the overload protection did its job) Interesting to read about the lack of protection on the powercab. Something I will now need to look into! Link to post Share on other sites More sharing options...
Phil47gwr Posted January 15, 2017 Author Share Posted January 15, 2017 Thanks for responses. I don't feel I have the soldering skills to fix the plug board as it's so tiny so I'm going to see if I can return it to Hornby. Regarding the overload protection on the Powercab, I've found the Tam Valley item (£27) but I don't know how to fit it. Link to post Share on other sites More sharing options...
Phil47gwr Posted January 17, 2017 Author Share Posted January 17, 2017 Just to bring everybody up to date: today I returned the loco to the merchant who accepted it without question (and without a receipt) for repair. That's what I call service! Link to post Share on other sites More sharing options...
RMweb Premium Izzy Posted January 17, 2017 RMweb Premium Share Posted January 17, 2017 Thanks for responses. I don't feel I have the soldering skills to fix the plug board as it's so tiny so I'm going to see if I can return it to Hornby. Regarding the overload protection on the Powercab, I've found the Tam Valley item (£27) but I don't know how to fit it. This would be like any other circuit breaker I would assume, although this does state that unlike apparently some others it cuts the power to both feeds. So you would connect it to the DCC command station/Powercab output leads and then the breakers output goes to the rails. I would expect that instructions/diagrams would be supplied with it, but you never know. Seems to be the same as their well regarded frog juicer circuits, just configured for CB operation. Perhaps by the end user if I read the various web pages correctly. I am sure if obtained from the likes of Coastal DCC they would advise. Izzy Link to post Share on other sites More sharing options...
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