Power pick-up problem?

[Airbuspilot]

We put most of our locomotives back into their boxes and stored them for the winter, I have just started to put them beck into service. A couple of weeks ago I took the first four and placed them on the track and all four worked perfectly. One week later two of the four refused to respond to the CAB (MX 32) and the iPad with Z21, testing on the programming track they both refused to read address's and would not read or write CV's.

Now, after a second week, one has started to work normally and the other still dead. I don't believe both decoders suddenly decided to fail (one obviously didn't) my feeling this has to be a power pick-up problem. Both engines have four wheel bogies and two pick-up shoes, disregarding the two wheels with traction tyres thats a lot of potential electrical connection. I have cleaned the wheels and pick-up shoes on the non responding loco and cleaned a section of track but still no luck.

I realise this is an impossible question as there are so many variables but, is this something that happens occasionally and is there a possible fix without having to dismantle the loco?

Robin

 

[dunnyrail]

We put most of our locomotives back into their boxes and stored them for the winter, I have just started to put them beck into service. A couple of weeks ago I took the first four and placed them on the track and all four worked perfectly. One week later two of the four refused to respond to the CAB (MX 32) and the iPad with Z21, testing on the programming track they both refused to read address's and would not read or write CV's.

Now, after a second week, one has started to work normally and the other still dead. I don't believe both decoders suddenly decided to fail (one obviously didn't) my feeling this has to be a power pick-up problem. Both engines have four wheel bogies and two pick-up shoes, disregarding the two wheels with traction tyres thats a lot of potential electrical connection. I have cleaned the wheels and pick-up shoes on the non responding loco and cleaned a section of track but still no luck.

I realise this is an impossible question as there are so many variables but, is this something that happens occasionally and is there a possible fix without having to dismantle the loco?

Robin

Well worth checking that all pickups connected. Try to check that all wheels and skates each individual side connected to each other with a Meter. A sticky plunger can often be the problem.

 

[Airbuspilot]

Well worth checking that all pickups connected. Try to check that all wheels and skates each individual side connected to each other with a Meter. A sticky plunger can often be the problem.

Thanks for the suggestion, good idea, I will give it a try.

 

[PhilP]

Check the skates are free to move up and down.. Give the surfaces that rub on the track a wipe over..

You say you cleaned the wheels? - Tyres, I assume.
Did you clean the backs of the wheels, where the carbon-brushes rub?
You don't have to get them super-shiny, but if you can run the loco upside down, cradled on your lap. You can use a cotton-bud with a little alcohol on it. Croc-clips onto the skates, should power the loco for you.

Check the carbon brushes, are not overly worn, and do not have ridges, which cause them to 'stick' in the holders.

PhilP

 

[Airbuspilot]

Thanks Phil, I didn’t clean the back of the wheels but I should have thought of that. The brushes look OK but I will have a closer look. Some of our locos are quite old so probably worth looking at replacement brushes.

Croc Clips worked on another problem loco but not on this one, I will give it another try.

Robin

 

[Greg Elmassian]

What Jon said, test every pickup point individually

 

[Dan]

Can you read CV29 to verify it is correct and matches your ipad/z21 setup.

 

[Airbuspilot]

Hi Dan, this locomotive is not responding with the MX 31 or Z21 on the main or programming track Which is why I think it is a power problem. The other locomotive which was dead suddenly started to work so with luck this might do the same.

 

[Greg Elmassian]

You have not identified the locos, but most locos have multiple paths for power pickup. To have them go out all at the same time is unusual.

I'd say open the locos, go right to the decoder with the programming track. That will QUICKLY determine if it is the decoder or the wiring.

The divide and conquer method of isolating where the problem is - is much faster.

 

[mike]

Not a isolation switch acedently moved?

 

[Airbuspilot]

I was hoping to avoid opening the loco but looks like I’ve no choice. I will make some continuity checks and clean the back of the wheels first and if that fails start taking thing apart.

Thanks to everyone for all the advice.

Robin

 

[Airbuspilot]

I was hoping to avoid opening the loco but looks like I’ve no choice. I will make some continuity checks and clean the back of the wheels first and if that fails start taking thing apart.

Thanks to everyone for all the advice.

Robin

The mysterious world of DCC.

Yesterday my dead loco sprang back to life and is working perfectly !!!

Probably an internal wire problem but I will keep an Eye on it for a while before resorting to surgery.

Thanks again for All the comments.

Robin

 

[PhilP]

It should not happen...
But I also found, that occasionally, a loco would just 'not do anything', but if lefr for a day or so, would then miraculously work again..

I don't know whether it was the 'computer' in the decoder, or (more likely) that in the Central Station. But a 'hard-reset (no power for a couple of days) appeared to sort it.