Short Circuit with one engine [DCC Controlled]

[Chrissaf]

Been doing a little troubleshooting. Turned the engine upside down and using a multimeter checked for continuity by putting the probes onto each opposite wheel. The meter showed that there was continuity across which would be the cause of the shorting. All driving wheels on engine as well as all wheels on the tender show continuity so I guess it's not a track pin or the like stuck inside. Any suggestions as what this could be please.

[Flashbang]

Hi

 

Look very carefully at the connector pin and contact fingers where the tender connects to the loco. If one is bent it is possible for it to then touch the otehr connection and cause a short circuit as you are seeing.

[Chrissaf]

Running railway this morning and after 5 minutes got a short. Message came up "DCC CONTROLLER ERROR Please clear the short circuit".

Checked everything and all good but short would not go away. After much unsuccessful troubleshooting took all engines off (3) and cleared short. It stayed ok. Put engines back on one by one and found that when I placed my Flying Scotsman on the track I got the short. It was this engine that was running when the short first occurred.

Have checked under engine and all looks OK. Any thoughts what could be causing the problem and why it just started all of a sudden. Wondering if dust has gotten somewhere that causes the short.

Any help and guidance is appreciated. This is my only engine with sound and the granddaughters favorite.

[Chrissaf]

Sounds like a typical TTS decoder failure. Probably a return to Hornby for repair [under Warranty if less than 12 months].

[The Captain90]

Thanks for your help. I am a complete novive here but after much research managed to remove the cover of the tender and got to the TTS Decoder. I removed it, and put one in (not TTS however) from another loco. Placed back on track and no short occurred so Chris is right again. Didn't reprogram the other engines decoder but will just purchase a new one for the Scotsman. Thanks again.

[Chrissaf]

Captain,

Even if the TTS is outside Warranty it is still worth going through the returns / repair process. It has not been unknown for Hornby to replace / repair  TTS decoders 'Free of Charge' even if outside warranty.

[ColinB]

It is funny that is what happened to my HST, running quite happily for 6 months then did exactly that. Initially I thought is was because I had it running a Ringfield 5 pole motor and the current was too much, but having got a replacement, I rechecked the motor current. The motor current is well within the limits of the decoder, even when stalled. The only other thing I wondered was if it had overheated, I did put it in a heatshink sleeve to stop it shorting out. The even funnier thing was while I was waiting to return it because of Covid issues, the TTS decoder in the dummy loco suddenly developed an even more obscure fault where it would power up without sound most of the time. Fortunately, Hornby replaced both of them.