Help with DCC select unit R8213

[Ashe]

I have started my first oo gauge layout since I was a boy, iv purchased a R8123 DCC unit and connected to the track using a Hornby's track conector. I followed the instructions in the user guide however if the connecting wires are connected to the track the unit display is a unreadable broken number, but if I disconnect ether one of the feed wires the unit display reads 03 and the green light comes on(fine) if I reconnect display goes back to broken number and green light goes out. Please has any one have an answer.

regards

ashe

[Chrissaf]

Ashe, welcome to the forum with your first post.

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Can you take a photo of this broken number and post it here. Note, if you do take a photo and post it back here, just be aware that photos have to be checked by admin and won't appear in the post straight away.

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The Green LED going out when you connect to the track, could indicate a short circuit.

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Is the track empty? meaning NO loco's sitting on the track (including any rolling stock as well). Take them off if you have anything on the track. Does the Green LED come back on. If it does, replace each loco or piece of rolling stock in turn back onto the track till you see which one causes the green LED to go out again. That loco or rolling stock may have a short circuit fault.

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Assuming the track is not yet fixed down. Another thing to do is remove any points that you have fitted in the layout. It has been reported that some Hornby points have left the factory with short circuit faults. With the points removed, does the Green LED come back on. If it does, reconnect each point in turn till the Green LED goes out again. This will indicate which point is faulty if your issue is due to a faulty point. There was a forum user only last week with a faulty point causing a short circuit.

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Another thing you could try. Remove the track power clip or power track from the layout. Take two wires from the track output of the Select controller and touch the wires, one to each rail of the main layout track with your fingers. Doesn't matter which way round. Does the Green LED stay lit and the display continue to show 03. If it does, then the power clip / power track is faulty (short circuit).

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Something else to check. Being DCC I assume you have fitted R8232 DCC point clips to the points. Double check these and ensure that they are fitted correctly. However, if there is something wrong with the way these clips are fitted, then removing the points as suggested above will show that up.

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By the way, the 03 appearing in the display (when things are working as expected) is completely normal and what would be expected to be displayed on the LCD at the point of powering up on a normally working Select controller. The 03 is the default loco DCC address that is given to all locos out of the factory and is the address that DCC controllers power up to.

[96RAF]

Just to add to what Chris has said in his last paragraph - watch carefully as your Select starts up and you wil see three sets of numbers...

 

either 10, 11, 12, 13, 14 or even possibly 15, which tells you the firmware revision state and can be important as to how you use the Select (which buttons to twiddle and how). This can be upgraded to the latest revision by Hornby if desired for a fee.

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then 30 which is the hardware revision state and can't be changed.

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Finally 03 which is the default loco address.

 

If you see these in order then the Select has booted up correctly.

 

Thereafter follow Chris's advice about checking for shorts.

[Chrissaf]

Just had a thought Ashe, this broken number in the display you spoke of, could it be "OL" if it is, it is not a broken number it is the letters OL meaning Over Load. With no locos running, this is a clear indication that the Select is detecting a 'short circuit' condition from the track.

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The only other time you should see OL displayed is if you are trying to operate more locos than the Select power supply is capable of supporting, thus drawing too much current.

[ff2nd]

That response, being instant, means that you have a short on your layout. I would not connect it to the layout until you have found it, as you risk damaging the Select. You will need to meter out your layout to find out where the short is. Daft question, do you have any reverse loops?

[Chrissaf]

Good point ff re: reverse loops.

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Ashe, a reverse loop is where a length of track goes into an arc (part of a circle) and connects back onto the same piece of track via a point, such that a loco travelling along that section of track ends back at its starting point but facing in the other direction. The act of looping back the track to the same starting point creates an unavoidable short circuit because the outer rail at the start of the loop now connects to the inner rail when it arrives back at the starting point. In a DCC layout, a reverse loop can be accommodated in the layout design by fitting insulated rail joiners at strategic locations, supplemented by an electronic device called a 'Reverse Loop Module'.

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If your layout is just basic ovals with individual sidings, then it will not have any 'reverse loops' in it. If it is an oval with a diagonal piece of track that say for example goes from the bottom left of the oval to the top right of the oval. Then you have created an oval with TWO reverse loops in it.

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If you think that you might have a 'reverse loop' in your track plan but not sure, then photograph your layout from above and post the photo back here, then many here will be able to look at it and advise if there is a reverse loop or not and what to do about it if there is one.

[poliss]

That response, being instant, means that you have a short on your layout. I would not connect it to the layout until you have found it, as you risk damaging the Select. You will need to meter out your layout to find out where the short is. Daft question, do you have any reverse loops?

DCC controllers are designed to cut out when a short circuit occurs. One way to test they are working properly is to put a coin across the rails to see if everything stops. If it damages the controller, then the controller is defective.

[Chrissaf]

Ashe, another potential source (unlikely but possible) for a short circuit is a Turn Table if it is installed incorrectly. Do you have one in your layout?

[Ashe]

Many thanks to all for help and posable Causes, interesting I had a play last night and I managed to use the control unit and get a loco to operate all be it a tad intermittent. I think that I have located a poor set of points and have removed the lay out and will redesign taking in to account the many valued pointers raised.

Regards Ashe

[Chrissaf]

and get a loco to operate all be it a tad intermittent.

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DCC needs a good clean electrical environment with robust connections between track pieces. If the layout is just temporarily loose laid with track pieces pushed together and unfixed, coupled with perhaps worn or loose track joiners. Then loco running can easily be intermittent. Also, depending upon how old the track is and where it was sourced it may also need a really good clean to remove traces of oil and grime.