Strange NCE Powercab Issue

[David41283]

Hi all,

 

I have encountered an odd issue with my NCE powercab.

 

Twice in the last 48 hours all the locos on the layout have started acting strangely. All of a sudden, they seem to have just two speed steps. They are still at step 0, then full speed at step 1, steps 2 and over make no difference. 
 

the first time this happened a loco had just come to a stop against the end of the fiddle yard and carried on pushing against this as I didn’t notice. Fairly innocuous, but the only odd occurrence that preceded the issue above. As there were only a couple of locos on the layout I solved the issue by resetting the decoders in each of them.

 

Today this happened again, just as I was messing about with consisting 2 DMUs. I cancelled the consist and all of a sudden everything, both involved in the consist and not, had developed the speed issue above.

 

The locos concerned are a variety of brands, with different chips, yet are all affected the same way, hence my belief that the issue is the controller. Even when this speed issue is manifest, the chip has still retained the address and the sounds work as normal.

 

i can’t see any reference to this in any forums or online anywhere, so hopefully someone can help!

 

thanks

[Ray H]

It might be worth disconnecting the PowerCab & taking the back off and making sure the Integrated Circuit - the long thing with lots of legs - is fully seated - press down firmly but not too forcibly.

 

It could be worth unplugging the PowerCab from the PCP immediately your problem re-occurs and then plugging it back in to see if that cures it.

 

Also worth checking that the power supply to the Power Cab is delivering the correct voltage - no more than 15v measured on the dc scale on a test meter. Alternatively, if you have another supply - even just 12v - you could try that.

[Tom D]

From what you have described, it could be that by resetting all of the decoders, the decoders have defaulted to original settings. In particular CV29, (Bit 2) which defaults to DC and DCC allowable running. What you have described, does sound as though you need to change the DC running to 'OFF', you can do this by adding 4 to the CV29 value for Bit 2.

Hope this helps.

 

Best regards

Tom D

[RAF96]

Is the Powercab set for loco zero running. If so it may have been selected and left with throttle on. Try a controller reset to clear its brain.

[Kaput]

53 minutes ago, RAF96 said:

Is the Powercab set for loco zero running. If so it may have been selected and left with throttle on. Try a controller reset to clear its brain.

 

Powercab doesn't have that ability.

[David41283]

I did wonder if I suffered a voltage drop for some reason, could the lower track voltage “trick” the locos into DC mode, resulting in the odd speed behaviour?

 

[Nigelcliffe]

19 hours ago, David41283 said:

 

the first time this happened a loco had just come to a stop against the end of the fiddle yard and carried on pushing against this as I didn’t notice. Fairly innocuous, but the only odd occurrence that preceded the issue above. As there were only a couple of locos on the layout I solved the issue by resetting the decoders in each of them.

 

 

What did you do to achieve "resetting the decoder".     That could be interpreted in multiple ways. 

 

Yes, it sounds like an issue originating at the command station.  Could be user-error (or button fault), could be internal fault.  Might be layout wiring (the idea of trying of "snubbers" at the far ends of the layout wiring raises its head).

 

 

- Nigel 

[David41283]

2 hours ago, Nigelcliffe said:

 

What did you do to achieve "resetting the decoder".     That could be interpreted in multiple ways. 

 

Yes, it sounds like an issue originating at the command station.  Could be user-error (or button fault), could be internal fault.  Might be layout wiring (the idea of trying of "snubbers" at the far ends of the layout wiring raises its head).

 

 

- Nigel 

At the time of the first fault, I only had two locos on the layout, which hadn’t been run for a while, so I assumed a decoder issue and reset CV8 to 8, I had to reprogram the addresses again, but this wasn’t a huge problem.

 

second time there were 5 locos on the layout so this is a bigger headache. I am suspecting that through a wiring issue or too many locos drawing power from a powercab system the power has dropped. I will try turning off DC mode on all my locos to see if this works. 
 

thanks for all the suggestions. 

[AndrueC]

I wouldn't blame the locos. It's more likely that one thing has gone wrong than that multiple things have all gone wrong in the same way at the same time. Have you changed anything recently?

Edited December 3, 2023 by AndrueC

[dasatcopthorne]

Maybe the rotary encoder in the throttle needs replacing.

 

This is what is connected to the thumb wheel inside the handset.

 

This is  easily done and involves de-soldering the current component and soldering a new one in. Available on eBay.

 

There's probably a Youtube video to show you how. I've done two or three.

 

The symptom is when you wind the wheel up/down, the step numbers jump all over the place.

 

Dave.

 

 

Edited December 3, 2023 by dasatcopthorne

[Nigelcliffe]

21 minutes ago, dasatcopthorne said:

Maybe the rotary encoder in the throttle needs replacing.

 

This is what is connected to the thumb wheel inside the handset.

 

 

If the encoder is suspected, then a squirt of contact cleaner into an encoder may bring it back to working for a while.  

Most likely it will still need replacing, but gives confirmation before doing the replacement.