Simmo009 Posted October 29, 2019 Share Posted October 29, 2019 Hello all, I have a strange situation.So, I have a DCC ready A3 (R3202). It has been running perfectly with a Zimo MX600 decoder. I have changed to the appropriate TTS Decoder, and that is when the problems start.I was able to assign an address to the decoder. Then i took it to the club last night to give it a run. It set off ok, chuffing away merrily. After a couple of metres, it stopped and restarted. This became more frequent. By the time it had gone about 6 metres, mostly straight run, it was shorting the circuit. Using paper to isolate the wheel one by one, the 'short' was being caused by the front and rear driving wheels. This loco has tender pick ups, but they do not cause a short. As a check, we put it on the DC layout, it didn't move, but neither did it cut out the circuit.The only thing that has changed is the decoder, so i am ruling out any electrical problem within the loco itself.We did not have a tester to hand, but that will be the next diagnostic step.Have any of you experienced this, or have any idea how to resolve it? Link to comment Share on other sites More sharing options...
Rog RJ Posted October 29, 2019 Share Posted October 29, 2019 It may be that you have disturbed something while fitting the TTS decoder. Re fit the old decoder to check the loco still runs ok with that decoder, or is the problem still there? Link to comment Share on other sites More sharing options...
96RAF Posted October 29, 2019 Share Posted October 29, 2019 Rigged for DC the blanking plate shorts out three pins at each end of the socket to coinect the wheel pickups with the motor and cater for directional lighting if fitted. When a DCC decoder is installed all eight pins are brought into play even if there is nothing connected to the inner four pins. The problem is a short between any of these pins and the outer four pins can cause exactly the problems you talk about. Check the socket for continuity between any pins that should not be linked. Some locos have been known to be miss-wired onto the wrong socket pins. Again check for this and any stry solder tracking pin to pin. Link to comment Share on other sites More sharing options...
Simmo009 Posted October 29, 2019 Author Share Posted October 29, 2019 Thanks for the fast responses.Rog - I will check that out, I had to move some wires to get the speaker into position. The previous chip is now in another loco, I will check that out and se if it runs ok in the new one.RAF96 - I doubt there is an inherent issue with the socket connections, as it worked 100% with the previous decoder. I will bear this in mind if a first fit goes wrong though.Will keep you posted.BTW, someone from the club has suggested the volume is too high. Is this likely? I understand the default setting for TTS cheps is step 4 on a scale of 0 - 8. Can anyone confirm this. Link to comment Share on other sites More sharing options...
96RAF Posted October 29, 2019 Share Posted October 29, 2019 Default TTS volume is 4. Individual volumes can also be adjusted. Link to comment Share on other sites More sharing options...
Simmo009 Posted February 15, 2020 Author Share Posted February 15, 2020 Sorry for the gap, I was having trouble logging in. Chip was tested independently of the loco, and is faulty. Did I see somewhere that Hornby have a no qualms exchange policy with TTS chips? Link to comment Share on other sites More sharing options...
96RAF Posted February 15, 2020 Share Posted February 15, 2020 Correct - it even includes user damage.Contact HCC about it - by phone is quicker. Link to comment Share on other sites More sharing options...
Simmo009 Posted February 16, 2020 Author Share Posted February 16, 2020 Cheers RAF, something to do on Monday. Will also check out my faulty Britannia chip. Link to comment Share on other sites More sharing options...
ColinB Posted February 17, 2020 Share Posted February 17, 2020 Yes, I have had quite a few replaced, never seems to be an issue, they are very easy to damage. The other thing that is relevant, from my experience the Zimo DCC modules are more tolerant of missing the DCC signal, so if the loco runs along a bit of dirty track then the the Zimo will cope with it better than a Hornby TTS module. Also TTS is probably drawing more current, so more succeptacle to a bad piece of track. Link to comment Share on other sites More sharing options...
Howbi Posted February 17, 2020 Share Posted February 17, 2020 Well I have only 8 TTS decoders going back to 2016. None have failed or been any problem, I can't see where they are more easily damaged than other makes other than by careless handling. As for coping with dirty track I find them no different to any other of the 10 makes of decoder I currently use. The current drawn through the decoder depends on the motor and ancilliaries.........HB Link to comment Share on other sites More sharing options...
ColinB Posted February 18, 2020 Share Posted February 18, 2020 Well howbiman all I can say is you have been very lucky, a couple of TTS units I did damage because of a faulty motor suppression capacitor, which incidently I didn't know was there. The other couple were basic issues with the unit, one worked OK as a DCC decoder but no sound (yes, I double checked the speaker and connections) and the other one didn't work at all. As for dirty rails, I stick by my original post and going by other peoples post, this does quite often happen. As with all electronics there will be a failure rate, generally in the first 50 hours, so getting a duff unit is not unusual. As I say, you have just been lucky and yes I know about handling procedures I am a professionally qualified electronics engineer. I used to work in electronic automotive diagnostics and yes the electronics on my car never went wrong, but I know loads that did, otherwise I wouldn't have had a job. I hate people that write posts like that, it is not helpful, I rarely get brand new broken locos but I know they exist. Link to comment Share on other sites More sharing options...
96RAF Posted February 18, 2020 Share Posted February 18, 2020 The vast majority of my TTS decoders are still alive and well, some of which go back to the very early days of TTS. Those few that have gone south have been due to my own mishandling, either poor physical installation or overloading the functions outputs or sound amp. I have never cooked one in normal service (except a Class 37 by overloading the lights using a kit) even though some are heat sleeved (not recommended these days), although they can get quite warm. In the early days of TTS I used an RM program to stress test the decoders by incrementing the speed setting by 10% every 30 seconds from zero to max and back again with each sound function being switched on in the interim, then off again later for toggled sounds. Volume was also cycled from datum setting to off to max as part of the operational check. The program was set to loop for a couple of hours and saved me having to sit at a bench and do the selections by hand and listen to the racket. I think I still have the program on one of the PCs. Link to comment Share on other sites More sharing options...
morairamike Posted February 19, 2020 Share Posted February 19, 2020 My 3 TTS decodershavd all.been fine the speaker on one decided to start playing up. Now use sugar cubes speakers better sound smaller fit in loco. Hornby changed the speaker no problemsPossible during the transportZtio. It moved and shorted. Link to comment Share on other sites More sharing options...
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