micky.b Posted May 19, 2019 Share Posted May 19, 2019 Hi all Hope you can throw some light on this. I have two 2bil sub emus.(Hornby) bought new and dcc ready at the time. I fitted a Hornby decoder to each unit. I don’t remember the R number but they are just standard as far as it goes. I set them with identical accel/decel settings as I used them in a consist. (Before I ran them together I ran them one behind the other to check that they both performed equally). They ran absolutely fine as a 4 set for around 2-3 years One day I noticed that they ran sluggishly and took a while to pick up speed. Here is the fault. I separated the sets and ran them one behind the other again. One unit accelerated and ran quicker than the other and not as they had done originally. Also when left as separate units in a siding, without any prompting or address from me one of the units, always the same one, would start off on its own. Looking on this forum, at all related decoder posts, I concluded that resetting the decoders would be the key. So I set both units CV8 to 8 as I had noticed. They both went to default 3 as I had also learned. Now after resetting their address numbers to the originals neither units move at all. I am not expert in dcc but I have a clue about it and can work things out with the manuals, however do I have to enter all the CV’s values again or do you think the decoders were fried from the start? Hope this makes sense to you and thanks in advance. Micky Link to comment Share on other sites More sharing options...
Fishmanoz Posted May 19, 2019 Share Posted May 19, 2019 Hi micky, I suspect neither decoder is fried. Given both don’t work, I’d be looking for something common to both decoders, not thinking 2 decoders are faulty. Given they both worked after a reset, try that again. In fact, have you tried either on address 03 after trying to readdress them to confirm that it worked? Apart from that, I’d be checking that your track is spotlessly clean, along with wheels, wheel backs and pickup tensioning on the wheel backs. Link to comment Share on other sites More sharing options...
micky.b Posted May 20, 2019 Author Share Posted May 20, 2019 Thanks Fishmanoz I didn’t try them on default 03, so I will do another reset and try running them both on 03 one at a time and see what happens. Micky Link to comment Share on other sites More sharing options...
Phil_Spiegel. Posted May 20, 2019 Share Posted May 20, 2019 It may also be worth remembering that not all decoders use CV8=8 to do a full reset, or even part of one.(AS part of my recent batch of TTS fitting, I came across many 'early' dcc decoders, which 'predate CV8=8 standardisation - and needed CV8=32 for example, and even a TTS decoder which appeared not to reset or reprogram .... it needed a longer break in the power AFTER programming before being made to 'start afresh' =when it then picked up its new address ..Decoders can also be locked against accidental change - but I don't know if CV8-=8 overides this ...in the types I use with a lock ( Accessory decoders - it is described as having to be 'unlocked' with a certain value in another CV BEFORE it will respond to othe changes ) Link to comment Share on other sites More sharing options...
micky.b Posted May 20, 2019 Author Share Posted May 20, 2019 Hi Phil, This last point I can understand as I mentioned whether having to re-map the CVs would be a requisite. Also some interesting thoughts about reset codes and resting time for decoders that have been reset. I think I’ll give it some more time to read up on these issues. Of course if I could remember the R number for these decoders it may help me to find out their reset values. Thanks for your pointers. Micky Link to comment Share on other sites More sharing options...
96RAF Posted May 20, 2019 Share Posted May 20, 2019 To add to Phil's statement...There are some controllers - not Hornby - where although the screen says the user action is complete the inner gubbins is still working away at it, so giving the unit time to 'catch up' makes good sense. Link to comment Share on other sites More sharing options...
morairamike Posted May 20, 2019 Share Posted May 20, 2019 Have you serviced the motors and the running gear. Possible the bearings are in need of a little oil. Are the CV 29 set to run only on DCC. Link to comment Share on other sites More sharing options...
micky.b Posted May 20, 2019 Author Share Posted May 20, 2019 I did check the CV29 for only DDC after the reset Mike. I cleaned the wheels, pickups etc when I noticed the erratic running. I’m fairly sure it’s a decoder problem. In the long run I think it may be easier to bite the bullet and make a purchase. Thank you all for your input. It has added to my education in matters DCC! Link to comment Share on other sites More sharing options...
Fishmanoz Posted May 21, 2019 Share Posted May 21, 2019 You could try swapping the decoders between the 2 locos. If the fault follows the decoder, then most likely that one is faulty. If the fault stays with the original 2-BIL, then that has the problem not the decoder. Link to comment Share on other sites More sharing options...
Bulleidboy Posted May 21, 2019 Share Posted May 21, 2019 The two normal Hornby decoders are numbered R8215 - this was superceded by R8249 - not sure this helps? There is also the Sapphire (R8245) - not sure how many use this - it's expensive. Link to comment Share on other sites More sharing options...
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