Demoralised DCC newbie

[Bochi]

I recently decided to take the plunge into DCC, not least because I want to do double-heading on my Port Road layout, and have an operating team with drivers and signalmen working separately.

But I can't get it to work at all. I have a Prodigy Advance 2 and a couple of Zen Black 8-pin decoders. I fitted them to a "DCC Ready" Hornby Compound and 2-6-4T after first checking that the locos run OK on DC. The hand unit and its box power up fine. The programming track has power. The chips are well seated in their sockets and the orange cable is in the marked corner.
 

But when I try to READ the address of the chip I get nothing back. When I try and program CV values into it I get "SEND" messages but when moving to a main track, the locomotive doesn't move and the DCC controller doesn't seem to recognise there's anything there. I get the same result with both locomotives.

I can't help feeling I'm missing something but the more nothing happens, the more frustrated I get and the less sense the manuals make, because, of course, I'm not seeing the results they say should happen when I go through the prescribed steps whether they are the steps in the Gaugemaster manual or in the Zen V12 booklet. 

Does this strike a chord with anybody? What could be going wrong?

[Ray H]

Have you got any means of checking the output from the Prodigy to track? Depending on how you test you might need to check volts on the AC rather than the DC range.

 

Once you've proved that is there you can trying connecting the prodigy to a short length of track and check again. That will then rule out any problems with the throttle and associated kit.

 

At the moment it is a little floundering in the dark not knowing where the problem is.

 

Do you have access to another known to be working DCC fitted loco?

[Bochi]

5 minutes ago, Ray H said:

Have you got any means of checking the output from the Prodigy to track? Depending on how you test you might need to check volts on the AC rather than the DC range.

 

Once you've proved that is there you can trying connecting the prodigy to a short length of track and check again. That will then rule out any problems with the throttle and associated kit.

 

At the moment it is a little floundering in the dark not knowing where the problem is.

 

Do you have access to another known to be working DCC fitted loco?

 

Thanks Ray. I don't have a multimeter. I do have some motors somewhere which run on AC or DC current so I could see if those turn.

I appreciate that it's all floundering in the dark. Alas, no, I don't have access to a "known to be working" DCC loco.

[Joseph_Pestell]

16 minutes ago, Bochi said:

 

Thanks Ray. I don't have a multimeter. I do have some motors somewhere which run on AC or DC current so I could see if those turn.

I appreciate that it's all floundering in the dark. Alas, no, I don't have access to a "known to be working" DCC loco.

Very difficult to build a layout without a multimeter. It's the best fault-finding tool. The cheapest are only about a tenner so you will soon make it pay for itself.

 

I am a bit puzzled about the idea of motors that will work on either DC or AC. 

[Bochi]

11 minutes ago, Joseph_Pestell said:

Very difficult to build a layout without a multimeter. It's the best fault-finding tool. The cheapest are only about a tenner so you will soon make it pay for itself.

 

I am a bit puzzled about the idea of motors that will work on either DC or AC. 

 

Multimeter on order. 

One of my other hobbies is building stuff out of Meccano. The old Meccano E20R and E15R motors ran on AC or DC. Rugged beasts.

[Free At Last]

If you haven't got any test equipment try the 'coin test' and put a short on the track to see if the controller responds to that.

[JimFin]

Remember that virtually all DCC locos will run on DC - so leave the loco on the test track and try running  it with your analogue controller. If it moves, the issue is with the DCC set up, if its static, the issue is with the decoder. Would give you a starting point to work from.

[Bochi]

3 hours ago, JimFin said:

Remember that virtually all DCC locos will run on DC - so leave the loco on the test track and try running  it with your analogue controller. If it moves, the issue is with the DCC set up, if its static, the issue is with the decoder. Would give you a starting point to work from.

 

Will try that in the morning, thanks.

[SRman]

Another thing to try is if the locos are not responding to the programming attempts, try dialling in an address of 3 on your controller to see if the locos move on their default addresses.

[Ray H]

11 hours ago, JimFin said:

Remember that virtually all DCC locos will run on DC - so leave the loco on the test track and try running  it with your analogue controller. If it moves, the issue is with the DCC set up, if its static, the issue is with the decoder. Would give you a starting point to work from.

 

I'd not recommend that from personal (and expensive) experience. We had a sound fitted loco on our O gauge club layout. We're still not quite sure how it happened but believe it got a bit too close to a dc fed track section with the consequence that it needed a new (sound) decoder.

 

Equally, am I not right in thinking that to run a decoder fitted item of stock on a dc layout it is necessary to have the relevant bit set in CV29? I will accept that the default does appear to be that the bit is set but I doubt that can be guaranteed and isn't a reliable way of determining whether a dcc system is or isn't working.

[MartynJPearson]

I use the Prodigy Advance 2 and issues I normally have with the programming track are usually do to cleanliness (of the track or loco wheels, not myself). When you send a message to the loco on the programming track, it will often judder a little bit, doesn't always happen but is a good indicator that something is getting to the loco.

 

Also don't be too hasty to remove the loco from the track - wait until the lights on the main unit have stopped flashing. Removing the loco too soon can result in data being set to a random value. 

 

I've no experience with those particular decoders but have used others from DCCConcepts with no issues. If you still have no joy, you might like to try sending the reset code (the decoder documentation will say what to do here) which will put the decoder back to its default settings - address 3.

[Brian]

Hi

Can I confirm some basic things with you.

1) The green plug on the rear of the PA is in fully inserted and the four wires in it are correctly stripped and secured by the green blocks screws. Remember the green plug pulls out to aid wiring and helps prevent damage to the main PCB when attaching/removing wires.

2) Your totally separate Programming track rails are actually separated from the main lines and the Programming tracks rails are feed from the 'Programming' output of the green plug. Obviously the Track pair of terminals go to the main layouts rails.  The programming tracks rail tops are spotlessly clean - Ideally clean them before programming begins.

3) As you don't have a multimeter yet, with everything powered up and no locos on the rails, I assume the PA display works? If so, momentarily apply a short circuit across any two main line rails (Coin dabbed on and off across the rails will do)   Does the PA go into immediate short circuit protection mode and the display change to SVdA.  

Dont forget if you do obtain a mutimeter the voltage on the rails is measured with the meter set to AC volts.

This video may help with initial programming if all the above are correct.....  Video re Programming

Edited May 7, 2020 by Brian
Edit to add video URL

[DLT]

Are you moving the loco straight from the programming track to the main layout?  Or are you doing an intermediate test in between?

You say they run ok on dc without the chip.  Have you then fitted the chip and done a test run (on a length of test-track) on dcc using the factory settings, before any programming or running on the layout?

 

My cautious (some might say over-cautious) leads me to test run it at every stage of the setup.  That way, as soon as it stops working, you know it was the latest stage that was the problem.  At the moment it sounds as though you can't tell whether its the loco, the programming, or the layout power that is at fault.

[Crosland]

1 hour ago, Ray H said:

 

I'd not recommend that from personal (and expensive) experience. We had a sound fitted loco on our O gauge club layout. We're still not quite sure how it happened but believe it got a bit too close to a dc fed track section with the consequence that it needed a new (sound) decoder.

 

Feeding DC (within sensible limits) to a decoder will NOT fry it. If you are saying you have DCC and DC sections on the same layout and it bridged the two then who knows what the DC and DCC controllers did. You are lucky they both survived in that case.

 

[Nigelcliffe]

Just another "absolute basics" check.....

 

The Programming Track output goes to a completely independent bit of track.   And that bit of track is not, in any way, connected to the main layout outputs of the Prodigy ?    

 

Because, if the two are connected, then "goodbye programming output".  They'll be blown, and the unit needs to go back to Gaugemaster for repairs.   Fortunately it is repairable, and Gaugemaster are usually very good with user-error damage.

 

 

- Nigel

[Barry Ten]

I'd agree with the comments to check if the locos respond to 03 (I never try to change an address without at least trying that basic test) and also the remark about making sure the green plug is firmly engaged. That's a gotcha that's caught me out on a few occasions.

[Nigelcliffe]

1 hour ago, Barry Ten said:

I'd agree with the comments to check if the locos respond to 03 (I never try to change an address without at least trying that basic test) and also the remark about making sure the green plug is firmly engaged. That's a gotcha that's caught me out on a few occasions.

 

 The usually accepted safe testing is roughly this sequence:

 

1 - fit decoder

2 - put on unpowered programming track and read a CV or two.  CV1 (which should be 3 by default on a new decoder) and CV8 (manufacturer's ID number) are my suggestion.

3 - change and read-back a CV of choice, can be something other than the address, so loco is still short-address 3.

4 - decoder now believed installed correctly, without a major catastrophic fault  (remembering that RTR manufacturers have had mistakes in the past which fry decoders). 

5 - now test run on the DCC powered main line.

 

-  Nigel

[melmerby]

17 hours ago, Bochi said:

 

Multimeter on order. 

One of my other hobbies is building stuff out of Meccano. The old Meccano E20R and E15R motors ran on AC or DC. Rugged beasts.

Because they have field windings.

Nothing to do with model railway locos which have permanent magnets.

 

[peach james]

3 hours ago, Crosland said:

 

Feeding DC (within sensible limits) to a decoder will NOT fry it.

 

True.  As long as it is DC.  Don't try pulsed power- for example, North American MRC Tech 3/4 power packs are horrible at frying decoders.   I know, because I toasted 3-4 of them with them, including a Lenz.  

 

As for having oops'd DC and DCC- I've managed that trick, and everything survived, by good luck.  But it is way best not to have DC and DCC anywhere near each other.  Unfortunately, I often end up having to with the Lego...and it is done under some haste usually for wiring...

 

James
 

[melmerby]

3 hours ago, Nigelcliffe said:

 

 The usually accepted safe testing is roughly this sequence:

 

 

4 - decoder now believed installed correctly, without a major catastrophic fault  (remembering that RTR manufacturers have had mistakes in the past which fry decoders). 

 

 

-  Nigel

Yes

I had a Bachmann loco (brand new) that was incorrectly wired for a decoder but worked fine on DC

IIRC it was the Great Western "ROD" which was subject to a recall.

[John Clitsome]

1. Remember that most multimeters wont give a true DCC reading. On mine the 16v supply reads as about 3.2 on the handheld multimeter - good enough if I know what to expect and for comparison purposes. Fortunately I have access to an Avometer which reads the correct figures as well - you can pick these up in the second-hand market for a reasonable price - new ones of course are silly money for our purposes.

2. I run the Prodigy A2 system and all the things said I have experienced. Read back can be quite temperamental and sometimes certain decoders just won't play nicely! One other consideration is put the loco directly onto Prog Track and not through any rolling road system which may be limiting the signal. Nevertheless just persevere and check all connections!

[melmerby]

2 hours ago, John Clitsome said:

 Fortunately I have access to an Avometer which reads the correct figures as well

 

Not if it's a traditional moving coil Avo it won't, They aren't True RMS reading and the frequency is too high for the transformer anyway.

[Bochi]

Thanks for all the advice which did enable me to track down some mistakes - hadn't installed one decoder properly after all, and misunderstood some aspects of programming.

I still have a mechanical issue with the 4-4-0 which has developed a stutter in reverse. It runs (but with a stutter) on DC but in the much slower DCC mode it grinds to a halt with a horrible ratchet sound as the motor, presumably, is spinning or trying to spin without engaging properly.

[Junctionmad]

On 07/05/2020 at 18:29, John Clitsome said:

1. Remember that most multimeters wont give a true DCC reading. On mine the 16v supply reads as about 3.2 on the handheld multimeter - good enough if I know what to expect and for comparison purposes. Fortunately I have access to an Avometer which reads the correct figures as well - you can pick these up in the second-hand market for a reasonable price - new ones of course are silly money for our purposes.

2

lovely things AVOMeters , my granddad gave me his , these days best polished and kept on the mantle piece , as a £10 quid DMM is more accurate 

[melmerby]

52 minutes ago, Junctionmad said:

lovely things AVOMeters , my granddad gave me his , these days best polished and kept on the mantle piece , as a £10 quid DMM is more accurate 

Still got my Avo 8 mk2 (?), worked perfectly but has been in less than ideal storage for years.

They are very accurate if in good nick and properly calibrated, wear of the jewels in the bearings of the movement was common with much use (they could be changed - a quite delicate job)

 

A £10 quid DMM? some even several times that price are pretty awful, my last few years of paid employment I worked at an instrument company that calibrated other firms electrical equipment and I spent a fair time

calibrating multimeters (including AVOs) and some of the Maplin and similar DMMs that were sent for calibration were truly rubbish accuracy.

Flukes were about the lowest priced DMMs that were really accurate and stable.

I still have a Fluke 73/75 Hybrid I made from recovered parts and that was very accurate last time I was able to check it some years ago.