[Alec Clayson]

I have just put anew decoder in a locomotive (6 pin direct.) With the controller set to 3, with no motion asked for, When the loco is put on the track it races away at full speed. The only way to stop it is either whip it off or remove the power from the controller, all my other locos work fine.
Short of trying another decoder has anyone experienced this phenomenon.
Loco runs really well in DC with blanking plug refitted.

 

[RFS]

Sounds to me that you have a defective DCC socket in that one of the track wires is connected directly to a motor wire, usually caused by a stray bit of solder joining the two. A DCC blanking plug does exactly that anyway which is why it runs fine on DC.

Were you able to program it successfully on the programming track initially? I would not put a loco directly on the fully-powered track until you have.

 

[Alec Clayson]

Thanks for the reply Robert
Yes straight on to Programming track hoping to read CV's and readdress,. but it wouldn't even do that .
I will try another decoder in it tomorrow.

 

[Graham Plowman]

In addition to RFS's suggestion, I'd be inclined to try a decoder reset and see what happens.

Few questions: What is the DCC system, what decoder is it, how old is it and where did you get it from ?

 

[Alec Clayson]

In addition to RFS's suggestion, I'd be inclined to try a decoder reset and see what happens.

Few questions: What is the DCC system, what decoder is it, how old is it and where did you get it from ?

Thanks for the input Graham, I'm running Railmaster with elink. Decoder is Dapol 6 pin direct imperium.
One major problem with decoder reset would be to catch the loco ( Graham Farish Black 5)😀 first.

 

[Alec Clayson]

Hello again All, many thanks for your replies. In conclusion after testing the Dapol decoder on my test rig and found no problems I swapped the decoder with another loco and hey presto all working fine, I conclude that the pins on the Dapol must be slightly longer thus causing the short. Can concentrate on some running now.