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Discussion Starter #1
HI all,
I got this engine about 8 months ago and I could never get it to program so it would run right on my switching layout. Well, I dug it out today and reset the decoder and in forward when I turn up the speed it takes off and keeps going with throttle down. It stops in reverse if I stop the throttle. I have the zepher express so I have been trying to setup that 3 cv mode in CV2, 5, and 6 and that won't work either. Did I get an engine with a bad motor or what? Any suggestions before I put it back in the corner of my engine drawer and say the H____ with it and forget it. I might be almost 75 but I can usually figure these things out by asking places etc. I do have decoder pro on my laptop but I haven't used it for a while and kind of forgot how to use it.

Thanks for help in advance
Bill, owner and operator of the Buffalo Creek RR
 

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I've had the "locomotive takes off on its own" problem with Digitrax decoders as well (including the DH126P, if I recall).

The solution:
You need to DISABLE the CV value that permits "dual running" (runs on DC as well as on dcc). That is, you need to make the engine "dcc ONLY".

I'm not sure of the CV value that controls it, but...
I use JMRI to set this, and it's a snap. I believe this is found (in JMRI) in the "basic" panel.

Once I set the decoders to "dcc only", that ended the "runaway" problems.

My hardware/control setup:
  • Roco z21start dcc controller/power box (with companion TPLink router for wifi)
  • Samsung S2 tablet running Roco z21 control software
  • MacBook Pro running JRMRI, connected to z21 via wifi
 

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Discussion Starter #4
I actually found out that one of the copper posts on my decoder harness was broke off and that is why it wont program. I have some coming this week I hope
 
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