Flying Scotsman DCC TTS shorting DCC circuit, but not DC

[Kford]

Exactly as the title suggests, my Railroad FS TTS worked for a moment (eBay purchase) but suddenly started throwing the shorting message on the Select controller (12 and 30 flicking between each other IIRC).

Works fine, silently, on plaine DC circuit, but not on DCC. 

When sound chip is unplugged it stops shorting, but I can't seem to get it to move. Might be my naïvity when it comes to DCC however. 

No obvious crossed wires or alien objects visible. 

Any ideas?!

 

 

 

 

[Rog RJ]

If you take the DCC chip out, you need to replace it with a blanking plug to allow it to run on dc (analogue).  It simply won't run without one.  You have to have either a DCC decoder or a blanking plug fitted.

[Chrissaf]

The TTS decoder will run on a DC Analogue control (albeit without sound) with the decoder fitted. It is designed that way as the factory default decoder configuration. Thus you could test it on the DC controller supply as a DC Analogue loco without having to replace the decoder with a blanking plug / plate.

.

Typical basic blanking plate / plug. Note the track shadows in the opposite corners. These corner tracks connect the pickup pins to the motor pins.

/media/tinymce_upload/ae9dabba77f30b96ded157eaa46aea65.jpg

[Kford]

Thanks for the reply. I was hoping to have it running on my DCC circuit, so I'm still searching for the short! Don't want to remove the DCC & TTS. Suspect it might be between the tender and loco. 

[96RAF]

The flickering numbers confirm that your Select v1.2 is operating on a 1-amp power supply as when it sees a short/overload the wall-wart drops its output voltage in self protection which causes the Select to keep rebooting, hence the startup numbers, it sees the short is still there and reboots over and over.

 

The likely cause of the short is the decoder plug touching metal under the socket or the socket has a solder bridging its connections. This doesnt matter on DC as the blanking plate also bridges the connections. 

 

If the loco is under warranty send it back or if not and you are happy fiddling inside locos undo the screws securing the socket to the chassis and closely examine the underside for problems. Also put a piece of insulating on the chassis under the socket .

 

You may wish to get your Select updated to v1.5 by Hornby so that you can operate all 29 functions of your TTS loco. contact HCC to get a returns number and how to pay the small fee for this.

 

Rob

[JemBobs]

Hi

I have had the same problem with the r8106 tts sound decoder.  It it pretty much brand new.  Should I send it back and get a replacement?

Thanks

[Fishmanoz]

JB, welcome to the forums. 

Given you say you have the same problem, then you can follow the same advice given to Kf - you can either fiddle around looking for the problem yourself or return it under warranty. 

 

And might I suggest, you are almost always better off starting your own thread with a new problem, then providing as much info as you can on it. You can then also give it a good, descriptive title, something like "R8106 TTS Decoder Causing Short with Select".