Gaugemaster Prodigy Advance 2 displaying oVLd

[ParkeNd]

I've just connected the above to my tracks for the first time. No locos on the tracks. Nothing across the rails like track pins etc. Never been used. But on switching on the handset displays oVLd which I believe means Overload as opposed to SVDa for short circuit. Cannot find any help for this. I have yet to install the Cobalt SS points motors so its quite feasible to my non-electrical mind that the random setting of the 6 points creates a short somewhere which will be "fixed" once the Cobalt Controllers get to reverse polarities wherever required.

 

Anybody able to help with this. DCC is new to me.

[ParkeNd]

[ParkeNd]

PS. Every opposing pairs of points have IRJs where they meet, and the exit rails on every frog have IRJs to guard against wheels sitting across the the frog and running rails. Continuity check with multi-meter produces a beep when both left and right running rails are touched with the probes - but I can’t find a short circuit. 

[Barry Ten]

Can you plug in a DC controller as a check?

 

If it were me I'd be looking for a location where you might have inadvertently switched the red and black polarities - eg a piece of track that got rotated 180 degrees after you'd soldered the droppers on.

[ClikC]

Does the unit display the error message when disconnected from the layout?

[Pete the Elaner]

If you mean the meter makes a beep with the prodigy removed, then this indicates a short & it is a matter of finding it.

If you have wired it in small sections then joined them together (which it looks like you have) then should be able to split it apart into smaller electrical sections then test each one. It may be a lot of work but may also be the only way to find out what is going on.

 

I always recommend wiring a layout in the smallest sections possible. This is exactly why.

 

[spamcan61]

Disconnect wires from your choc bloks one at a time until the meter stops beeping that will at least narrow it down.

[NGM]

First check the Prodigy not connected to the layout, if it still does it there's your problem, if it's ok test it connect to one bit of track away from the layout just to confirm it's working, if it's all working fine you have an issue with your wireing.

[ITG]

Really an alternative way of proving what has already been Said above,  but if you have a Multimeter, try testing for continuity across left and right rails. Likely this will give a positive continuity as that in effect is the short you have in your wiring, but if you are able to sectionalise the wiring, then retest continuity, sooner or later you’ll find the error. 
 

Doubt it can be anything to do with not yet fitting Cobalts. As an aside,I had a short, but I had already connected my ADSX point decoder Unit and motors (comparable to your Cobalts being connected I guess) and my short was caused by omitting to modify the underside of one Peco electrofrog point - thus causing the frog Power switching capability of the ADSX to conflict with the unmodified frog.

[ParkeNd]

Thanks for suggestions - much appreciated. If Prodigy disconnected from main line there is no oVLd message. Trying continuity across Left and Right rails anywhere on the layout produces a beep. Trying continuity between ANY left hand rail and ANY right hand rail anywhere on the layout produces a beep - even though the passenger set of rails and the goods shed set of rails are deliberately quite separate ie there is no set of points between them. Moving on to the DCC bus wires - there is continuity between left and right wires in both sets of choc blocks that terminate each end of the bus. That confuses the heck out of me - surely the choc blocks can’t be shorting?  I will upend the board tomorrow, reconnect the Prodigy with the board vertical against the wall, and disconnect the dropper wires between the choc blocks one at a time and see if the oVLd message goes away. After that there’s only replacing all 6 points with brand new ones modified again - I have 4 of the 6. I no longer have a DC controller so that angle isn’t available to me. 

[WIMorrison]

The fault is almost certainly in your wiring and not in the construction of the turnouts.

 

as suggested earlier you need to start disconnecting bits until the fault disappears and that will show where the fault is. 
 

it is easier (and less dangerous for your  command station) to use the multimeter to trace the fault. You can have set to beep and at the point it stops being that is where the fault lies.

 

unfortunately there isn’t a lot anyone here can do to solve your issue - you just need to track down the incorrectly connected wires.

[Izzy]

Do you have an odd piece of plain track laying around to which you can connect the Prodigy and run a loco on? Just to confirm that there is no issue with the DCC system itself when connected to track, that it works okay/properly before going down the ‘check all the board wiring’ route. It does sound like a board fault TBH but may be best to double-check first. I would also use a MM to do the checking. 
 

Izzy

Edited December 26, 2020 by Izzy
auto correct correction!

[ParkeNd]

Yes  I have half a box of track. And I also have the one metre long programming track at the front of the layout which is not powered of course and has no continuity across the left and right rails. 

[BokStein]

8 hours ago, ParkeNd said:

Moving on to the DCC bus wires - there is continuity between left and right wires in both sets of choc blocks that terminate each end of the bus. That confuses the heck out of me - surely the choc blocks can’t be shorting?

 

Have you fitted bus terminators (such as these)? If so, disconnect them and test the continuity again.

 

8 hours ago, ParkeNd said:

I will upend the board tomorrow, reconnect the Prodigy with the board vertical against the wall, and disconnect the dropper wires between the choc blocks one at a time and see if the oVLd message goes away.

 

NO! Why risk buqqering up £350ish of kit when you have a continuity tester? Disconnect until the bleeping stops!

[ParkeNd]

I didn't fit the suggested "capacitor/resistor" filter across the ends of the bus wires because, although I had the parts, I didn't think my length of track was long enough for the square wave to deteriorate. But if I put the red probe of the multimeter on the screw in the red wire side of the choc block that just stops it being just a wire end, and the black probe on the screw of the choc block at the end of the black wire the multimeter beeps. Same happens the other end of the bus wires.  See picture above of underside of the board.

 

And Yes - I already plan to disconnect and put away the Prodigy and use the meter. If I understand W I Morrison's post above then if I put the meter into Continuity mode and place one probe on LH rail and the other on RH side of rail on each length of track and point it will stop beeping when I reach where the short circuit is.

 

"it is easier (and less dangerous for your  command station) to use the multimeter to trace the fault. You can have set to beep and at the point it stops being that is where the fault lies."

 

[WIMorrison]

That is exactly what I am suggesting

 

[Brian]

Hi

Before you start taking the wiring apart, and as you're a DCC user and have by the looks of things Electrofrog points throughout. Plus you also have rail feeds to all rails, you need to ensure you have Insulated Rail Joiners (IRJs) installed in BOTH vee rails leading away from all electrofrog points,  not just those points that are opposing.   

If you have metal joiners on any Vee rail end replace them with Nylon IRJs

 

Place them where I have shown the red line cutting across both rails...  (Plus of course anywhere else off the picture).

 

Edited December 26, 2020 by Brian
Edit to uploaded image

[ITG]

 

.......... it will stop beeping when I reach where the short circuit is.

 

Well, yes, (and hopefully not teaching you to suck eggs) but only if you first disconnect underboard cable sections into ‘bite-sized’ chunks. Apologies if obvious, but just wanting to save you a lot of wasted time!

[RAF96]

I use a 9v battery operated buzzer simply connected across the rails when wiring in droppers to a bus. If I cross connect then it beeps. Controller is obviously not connected yet.

 

I did meet a problem using Brimal CN165 connection blocks as they have a bi-colour led and resistor build in as a live track indicator. The led and resistor pass enough current to set the beeper off so I had to lift a leg on the resistor of each board until the bus wiring was complete, then resolder them down again.

 

Bus terminators would give the same problem. Leave them off until the end.

 

It is not unknown for Hornby points to be faulty out of the packet, but hand made points would obviously be unlikely to show this problem. Peco points also seem more reliable, but worth checking that the jump wires are as they should be.

[ParkeNd]

Thanks for additional comments. I feared at one stage this morning was going to be a morning of blank results. I did every test proposed. Interrupting each dropper feed (black and red at the same time) at the choc blocks left the meter beeping when applied across the ends of the bus wires) every time. None of the soldered feeds had been reversed anywhere. But clearly the red and black bus wires are shorted along their entire length. So I figured the problem had to be the track. So I went back to WIMorrison’s proposal. 

 

On the two photos below the short length of Point 3 marked in black felt tip pen on the board is the only place on the tracks where there is NO beep with probes between opposing rails.  So is it likely that this is the source of the problem? 

[Barry Ten]

Another thing to watch for with IRJs as it's just possible to get rail to rail contact if the ends haven't been cut cleanly - this has happened to me once after some thermal expansion caused the rail ends to close up the gap (admittedly in N, but I think it might happen in 00).

 

I know its a bit late now but I wouldn't dream of wiring up a section of layout without testing each bit individually.

[smokebox]

You need to use insulating rail joiners on all frog rails

 

Edited December 26, 2020 by smokebox
Added text

[ParkeNd]

Thanks - they are insulating rail joiners. There are IRJs on every frog rail. 

[ParkeNd]

Thanks Barry Ten. I did check continuity of every lead at the point of connecting them. But I still got burned because I hadn’t checked, and thus found out, that there was continuity ACROSS rails. Didn’t have this problem with unmodified Peco points on my N Gauge layout. 

[ClikC]

I suggest the half-splitting technique.

 

Find a convenient location, approximately separating the layout into two halves.

 

Continuity test both halves of the layout. Hopefully, one half should have the fault, the other half should not.

 

repeat this process until you locate the short.

 

Regards 

 

Matt

Edited December 26, 2020 by ClikC