Model Railway Forum

I have a DCC Problem. I have tried to explain the situation on more than one Model Railway Forum and all I get are standard basic responses straight out of the "Troubleshooting Manual", totally ignoring what I have written in my post. I appreciate people are trying to help but so far it hasn't helped. This is my first experience with DCC, although I got my DC first train set way back in 1960.
I do not have a Model Railway Layout at present as I moved house 3 years ago (downsized) and am undertaking a 5 year project to completely renovate the house I have moved into. I am also having to sell a lot of my collected locos and rolling stock in order to help fund my renovations. So to sell the loco's I have set up a test track on a piece of floorboard to ensure they run properly before I sell them.
On the same floorboard I have a second track. This track is for me to acclimatise myself with DCC concepts. As it is only a single track, it is in effect my program track. I purchased a new NCE Powercab starter system for me to use.
I followed the relatively simple instructions for connecting wiring to the track and then setting up the NCE controller to operate the system.And then I followed the also simple instructions to test a DCC fitted locomotive on the track...........and that is where my problem started. Nothing happened, the locomotive did not move.
Having worked on DC model railways all my life off and on, I knew at that poit that I needed to test other locomotives, re-test the connections and ensure that the wiring was in fact connected to the track properly.
In brief I tested a number of locomotives -Factory fitted Decoder, DCC ready with Decoder fitted, DCC ready with a different decoder fitted. Ran a DCC ready on my DC track, then fitted a decoder and tried to run it. I tried Hornby 8 pin deoders and Bachmann with 21 pin decoders. Everything produced the same result - no movement, no lights and no sound.
I even turned off the DCC, connected my DC conroller to the DCC wring and track and ran a DC locomotive perfectly on the same track.
I next tried to read a CV from all my loco options and the result was the same for all locomotives - "Cannot Read CV".
So my thoughts then turned to whether the Powercab controller was the problem. OK it showed that it was sending messages - but did they actually talk to the decoder? When asking to read a CV, did the controller actually send the message it was asking or was it that it could not receive the response.
By accident, I got a partial answer to this. I had two class 08 diesels on the shelf, both green livery but one was DC and one was DCC fitted. I put the DC loco on the track by mistake and connected the Powercab to the power, and...........the controller "buzzed". So that told me that the Powercab was at least getting a connection to the track.
I am at a loss as to what to do now.

If this has been repeated elsewhere apologies, but first of all make sure the DCC test rails are spotlessly clean and also clean the loco wheels (especially if they have been stored for any length of time).

Do you know the addresses of your DCC locos? Have you changed them from the default address of 03?
To eliminate this write the value 8 to cv8 and it will reset the decoder to factory settings including setting the address back to 03.

From what I remember the Powercab has a twin port plug to connect the controller - make sure you have it plugged in the right one as only one will actually power the track.

Hi

Your NCE PowerCab is an excellent choice. I have used one for several years.

Start from the basics.....Check..
Is the red LED lit on the PCP when you turn on the mains power?
With the red LED at the bottom the cable from the handset must be in the lefthand socket.
The cable from the handset to the PCP is the flat one. Do not use the coiled cable.
Does the Handset light up and show a display correctly?
If any of the above are not correct, then check the power supply for an output and that the moulded barrel plug is firmly in the socket on the rear of the PCP. Check also that the flat cable is securely plugged into both the Left hand PCP socket and the handsets socket.
If the above are all correct then...
Check the two wires are correctly terminated into the small removable black plug-in connector on the rear of the PCP. Also that the connector is plugged in securely.
Check that the connection to the rails is NOT via a Hornby plug-in track power clip or a Hornby power track section, as these can have a capacitor inside which is not suitable for DCC operation. Ideally the two wires from the PCP should be soldered to the rails.
Without special switching or using a NCE programming adaptor and a dedicated Programming track isolated from all other rails, the PowerCab uses the main tracks for programming. When Programming / reading any locos decoder ensure only one loco is on the rails while programming.

If you have access to a multimeter it will really help in fault finding. They dont have to cost a fortune if you don't own one, Less that £15 will buy a meter suitable for most model railway operations. It can check on its 20V DC range or higher voltage setting that the power supply is sending around 16 volts DC to the PCB. This is checked by removing the barrel moulded plug from the PCP and inserting the meters red probe into the inner tube of the barrel connector and touching the black leads probe onto the outer area of the barrel. With the PSU On at the wall socket you should read a DC voltage of around 16volts DC.
If all is good, then reconnect the power supply Unit to the PCP and assuming the handset lights up ok, switch the meter to its AC voltage range of 20 volts or higher. Now test across the rails to see if any AC voltage is present - you should read around 13 to 15 volts AC on the rails. Note: a standard mulitmeter will not give a 100% accurate voltage reading of the DCC power, but it should be good enough. If no rail volts are present turn your testing to the PCP. Check the small plug-in Black connectors terminals for AC voltage. If no volts are present its likely the plug either end of the flat handset cable isn't inserted correctly or its faulty.

One last thing to ensure is that no other power source (DC Controller or anything else) is connected to the rails the PowerCab is to feed.

Report back findings for any further assistance.

As has been stated, clean rail tops and loco wheel rims are essential. All new DCC Fitted locos and new decoders are set to a default address number of 03.

Thank you for your bulk standard reply. I will not comment except to say my post explained that I had covered the basics and that was why I was making the post.

Your point about a multimeter is interesting. On another forum I reported on my findings using a multimeter and the response I got back was that a MM was not that beneficial with DCC as the output from the track was different depending on the task in hand.

I assume your decoders are fitted the right way round? I have been DCC modelling for some years, but very recently I put a 21pin decoder into a loco upside down - it took sometime before I realised the mistake. Sorry if that is a bulk standard suggestion.

SquiddlyDiddly666 wrote: ↑Sat Apr 01, 2023 9:10 pm Thank you for your bulk standard reply. I will not comment except to say my post explained that I had covered the basics and that was why I was making the post.

Your point about a multimeter is interesting. On another forum I reported on my findings using a multimeter and the response I got back was that a MM was not that beneficial with DCC as the output from the track was different depending on the task in hand.

Well, i'll try and not be Bulk or be Standard!!!
The comment re a multimeter is utter nonsense!

You are of course welcome to do whatever you want in future, all I was doing was ensuring that all the basics were looked at and ruled out one by one as necessary! That is the fundamental method of fault finding.
You haven't said if the red LED is lit, The flat cable is in use and that the flat cable is plugged into the left-hand socket with the LED at the
bottom. That the PCPs small black track wire plug is fitted correctly and its wires inserted correctly. Whether you're using Hornby plug-in power clip or power track section. Whether other locos were removed from the tracks when programming / trying to read! All are necessary to ensure the DCC operates correctly.

To note and risking "Bulking" here!! The PowerCab cable takes power from the PCP and passes it through the handset and returns the track power back via the flat cable to the PCP then out to the layouts rails. If the coiled cable is used or the flat cable is in the wrong socket or it has a damaged plug on one end then rail power cannot get back to the PCP and out to the rails.

Finally, a year or so ago I had a PowerCab reported not to be working, though the display was OK. It was sent to me to look at and I found that the PCP printed circuit board had not been factory soldered fully on the connection to the black track socket, resulting in no power to the rails. This could be the cause?

I have only put one decoder in a loco. All the others are either factory fitted or put in by previous owners. So I can't believe that would be the problem on 5 different locos.

Good chance it is the PowerCab or wiring I'd have thought in that case

I have read all your posts and replies here and on other forums and after a long consideration I have come to the conclusion that something is wrong somewhere.

Goingdownslow wrote: ↑Sun Apr 02, 2023 6:11 pm I have read all your posts and replies here and on other forums and after a long consideration I have come to the conclusion that something is wrong somewhere.

Yeah. Thats about the sum of it!