LNERGE Posted May 26, 2019 Share Posted May 26, 2019 I recently bought two secondhand Hornby point decoders. Both do something weird from output 1. I've tried various things to alter what they do but nothing seems to work. Both units fire a solenoid point motor from output 1 but it fires straight back again. By altering the CV settings i can alter it slightly but not very much. Any ideas? Link to post Share on other sites More sharing options...
HLT 0109 Posted May 26, 2019 Share Posted May 26, 2019 Can't think of anything but a bit more information might help: what point motor(s) are you using and what DCC system arer you using? Have you fitted the R8247s to different points or are you replacing one decoder with the other on the same point? Do outputs 2, 3 and 4 work properly? Are you sure the decoder is firing again or is the point rebounding with the aid of the spring? What make of points are they? Sorry for so many questions - thinking aloud really! I have about a dozen R8247s and not had your experience. Harold. Link to post Share on other sites More sharing options...
LNERGE Posted May 26, 2019 Author Share Posted May 26, 2019 Ports 2, 3 and 4 on both units work fine. I’m using a Hornby Elite and in this instance I’m driving peco surface mount point motors with peco points. I can hear a ‘tick’ ‘tick’ ‘tick’ from a point motor attached to port 1. If I call it to reverse it drives back half a second or so later. If I manually push the point to reverse again it drives back to normal. Each ‘tick’ I hear is it driving towards normal. Another side effect of having something attached to port 1 is it’s constant ‘ticking’ keeps the capacitor drained making the other ports weakened. Link to post Share on other sites More sharing options...
WIMorrison Posted May 27, 2019 Share Posted May 27, 2019 To identify if it is the motor, unit or point at fault a) remove motor from point and see if it works correctly when switched by decoder - if it does point is at fault b) remove motor from point and try motor on another decoder - if it works correctly then decoder is at fault c) try a known good motor on the decoder and switch using decoder - if it doesn't work then decoder is at fault Link to post Share on other sites More sharing options...
LNERGE Posted May 27, 2019 Author Share Posted May 27, 2019 It is definitely output 1 at fault. It reads the same as the others though. Link to post Share on other sites More sharing options...
HLT 0109 Posted May 27, 2019 Share Posted May 27, 2019 Sounds as if the R8247s are faulty but, to have two with the same, unusual problemis is strange. Something to try not mentioned previously would be to swap the wires from output 1 to output 2 (and vice versa) and see if the same point displays the problem or if the problem moves to the other one. If the problem moves, then the R8247s should be returned for repair, exchange or refund - easier of bought from a retailer rather than a private seller. Link to post Share on other sites More sharing options...
RAF96 Posted May 27, 2019 Share Posted May 27, 2019 You could try a reset just like a loco - write value 8 to CV8. This sounds just like a problem caused by a bug in the Hornby Select controller (only at v1.1, no other versions affected). The Select v1.1 bug scenario is this: If port 1 is activated the R8247 will start to pulse on/off rapidly. If a point motor is connected to the port it will discharge the on-board CDU and keep it flat such that the unit will not operate a point on any other port. If the unit is powered down port 1 will reset and the unit will work fine until port 1 is accessed again. If any other ports are selected first then the unit will work until port 1 is next used whereupon the unit fails again. If the system is left powered in the failure state it is possible for the output transistors to fail completely. The pulsing is not easy to detect and the chance of final failure makes diagnosis also difficult. The main problem is the R8247 can be repaired or replaced only to fail again as the Select v1.1 bug is the root cause. I would say this is what happened and the seller off loaded them. The best advice is never to connect an R8247 to a Select at revision 1.1. I would also be wary of using these dodgy R8247s with your Elite until you have spoken with HCC - mention the Select bug. 1 Link to post Share on other sites More sharing options...
LNERGE Posted May 28, 2019 Author Share Posted May 28, 2019 Many thanks. The pulsing on/off is the symptom i'm seeing. I've just tried calling port 1 with no load and the other ports remain effective. It was definitely not the case with load attached. I have tried the cv8 reset to no avail. All ports read 255. Link to post Share on other sites More sharing options...
HLT 0109 Posted May 28, 2019 Share Posted May 28, 2019 If the problem is what RAF96 has suggested, surely the solution is to upgrade the controller's software - but OP is using Elite rather than Select. Link to post Share on other sites More sharing options...
RAF96 Posted May 30, 2019 Share Posted May 30, 2019 On 28/05/2019 at 21:12, HLT 0109 said: If the problem is what RAF96 has suggested, surely the solution is to upgrade the controller's software - but OP is using Elite rather than Select. What I was trying to get across was that the R8247 PADs were probably damaged by a previous Select v1.1 user, who flogged them, but the problem is manifest using any controller. Repairing the R8247 if a reset hasn’t sorted it will make it work fine with the Elite. The problem is external to either the PAD or the Elite. The problem is only of ongoing concern if you have a Select at v1.1 and want to operate PADs - the answer is don’t until you upgrade the Select firmware. 1 Link to post Share on other sites More sharing options...
LNERGE Posted May 31, 2019 Author Share Posted May 31, 2019 Grrrr. I bought two new ones. They do the same. I am using an elite so wasn’t expecting this. Link to post Share on other sites More sharing options...
RAF96 Posted June 2, 2019 Share Posted June 2, 2019 On 31/05/2019 at 20:33, LNERGE said: Grrrr. I bought two new ones. They do the same. I am using an elite so wasn’t expecting this. Reset Cv8 to value8 ? Link to post Share on other sites More sharing options...
LNERGE Posted June 2, 2019 Author Share Posted June 2, 2019 Tried but no difference. Link to post Share on other sites More sharing options...
RAF96 Posted June 3, 2019 Share Posted June 3, 2019 (edited) 11 hours ago, LNERGE said: Tried but no difference. Contact HCC then. edit - what are the date codes on the lower case and CV 7 value if you can read it. Edited June 3, 2019 by RAF96 Link to post Share on other sites More sharing options...
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