Accessory Decoder - R8247

[badgers]

hi  you good men out there,can any one help ,over powerd my r8247 with too much 

power and i think i may have burnt it out ,can these be repaired and if any one knows 

where  ,  or do i just put in the bin and buy a new one ,

 

badgers

[Chrissaf]

"over powerd my r8247 with too much power"

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This, on the face of it, seems unlikely assuming you haven't substituted the genuine Hornby PSU for something else that was inappropriate. The outputs are designed to work with point solenoid motors, these are very near to a short circuit when connected across the R8247 output. I believe when the output is configured to provide a permanent output (for signals for example) the output uses current limiting protection. Thus being 'burnt out seems unlikely to me, faulty yes but burnt out no.

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What did you do that makes you think it is 'burnt out'?

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One thing that happens quite a lot with these R8247's, is that they lose their configuration for no reason, typically after a transient short circuit on the tracks. Losing configuration gives the impression that the R8247 is completely non-functional. Before concluding that it is faulty, I would perform a factory reset (assuming you haven't got a Select controller) and re-programme your port addresses. If you have RM / eLink (or Elite) then write value 8 to CV8 using the LOCO configuration screen with the R8247 attached to the programming output. But before that, try reading the R8247 configuration in the Accessory Decoder setup screen. If RM cannot detect the R8247 at all, then it is truly faulty. If you have a Select controller then just try re-configuring your port addresses as if it is a first time new installation. It may start working again.

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If it is outside Warranty, then Hornby may have a standard repair charge that is cheaper than buying a new one. I suggest contacting HCC by phone and enquiring. If there is a 'standard' charge then please report back here as that information could be useful to us all.

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Peter's Spares is an authorised Hornby Service Centre, but I think they are more geared up to repairing rolling stock. I would suggest Hornby themselves as a better bet for undertaking repair of controllers and accessory decoders.

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PS - This should have been posted in the DCC section.

[96RAF]

Tell us step by step what you did badger.

What you had connected to which bit and what sequence of events led up to the big 'oops I fried it' moment.

Does it smell of 'burnt out'.

[badgers]

firstly thanks for your comments, what happened was i had a 12 transfromer ,which i use for various items and i accidently connected direct too the decoder , and crossed the wires for my points on my setup,and when i switch on the power,three of my points tried to operate at same time, and the decoder went hot and was smelling, after i realised what had happened, i corrected my wireing ,and tried too set up the decoder with my select unit it just would not work anything ,suggestions  welcomtested my select and that is ok.

badgers

[96RAF]

So you applied 12V DC into the acc-decoder A-B ports, which was expecting around 15V DCC. Without a wiring schematic for the acc-decoder I'm not sure if it would/should have 'cooked' on DC input or not or self protected.

As to cross wiring some points motors to the various +C- ports. This in itself usually means the motor doesn't work at all or only works one way, but wouldn't cause the acc-decoder to fail.

Over to some other more knowledgable helper.

 

[Chrissaf]

I think if it went hot and was smelling, then it is toast, it is no more, and as it was user error you can't in all honesty claim warranty (assuming it was in warranty). I think in the same situation, I would chalk it up to experience and buy another.....

[96RAF]

Any further info on this one badgers.

If it was terminally toasted and you have replaced it there is nothing to lose by taking the top off the dead one and posting a photo of any obvious burnt bits, which may help others one day, or it may even be possible to mend it yourself it say a simple capacitor has blown.