Loco moves when power turned on

[Ch4lkst3r]

Hi,

 

I've got a Graham Farish Warship factory chipped and when I turn the layout power on it moves an inch along the track.  None of my other locos do this.  Any ideas on how to resolve this?

 

Thanks,
 

Iain

[davidw]

Can you get a replacement, or try a different decoder?

[Nigelcliffe]

Some guesswork as to causes:

 

Can you try the loco on a different DCC system ?   Or, at a minimum, can you disconnect your DCC system from the layout, connect to a short piece of track, and see if the problem persists ?   With these, I'm suspecting the layout wiring, and for a little while, the loco thinks its seeing "DC" rather than DCC.     You could also try changing CV29 in the loco to disable DC running to see if that fixes things. 

 

 

And, a longer shot, which DCC system ?   (I'm wondering if its like the older ZTC systems which didn't put out a stable DCC signal for a second or two).   

[Ch4lkst3r]

Thanks for the advice.  I've turned off DC running on the loco and that fixes the problem.  Strange thing is that it's only when my NCE Powerpro starts that it does it.  If I just turn off track power and then turn it back on it doesn't move.  Anyway the problem seems cured.

[Nigelcliffe]

This suggests it may be a wiring issue, with the loco thinking that the power is DC for a while, then deciding its actually DCC.    

 

It may be wiring (inadequate diameter, poor joints), and it may not be near where the loco is located, but elsewhere on the layout.  But, it may also be some sort of interference from other locos (or accessory decoders) on the track during startup.   You could try experimenting with "snubbers" which are a capacitor and resistor fitted to the ends of the DCC bus wires around the layout, that may influence things (or it may not).

 

- Nigel