Class 40 locomotive

[Bill888]

I have just bought a Class 40 locomotive with DCC fitted and TTS sound (40164).  I have also just bought the Mixed Freight train set (digital) with a Select controller version 1.2. I live in NZ which explains why both the set and the loco are 'older' stock.

The two engines on the set operate fine on the track - together and separately.  However the Class 40 loco will not run at all.  When I place it on the track and try to assign an address using Select on the controller, the controller goes into 'spasm' - a half readable code flashes on the screen pulsing in time with a clicking from the locomotive.  I have tried resetting the controller but no fix.  I am wondering how compatible this loco is with this version on the Select.  I am also wondering whether I have damaged the loco.  Any help would be appreciated.

[Rog RJ]

Sounds like the loco has a short circuit on it, causing the Select to continually cut out and restart.

[96RAF]

The loco should work fine with the Select except that with version 1.2 you will be limited to nine sound functions. If you want to use the full set of sounds your Select needs upgrading by Hornby to version 1.5.

 

I agree with Rog about a likely short. Make sure the loco is properly on track as there are a lot of wheels under a 40.

Rob

[Bill888]

Thanks for that.  How is the short in the loco fixed?

Bill

[Chrissaf]

It is impossible to tell you exactly what is causing a 'short circuit' if that indeed is your fault. There are just too many possible options. But initially, if you intend to try and fix this yourself rather than sending it back, I would focus on testing the TTS decoder first - see below.

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What is causing a 'short circuit' is far harder to find than an 'open circuit' (break in an electrical path). With a 'short circuit' you would need to disassemble the loco and use a multi-meter set to measure 'ohms' (resistance). A 'short circuit' will show up as either zero ohms, or a very low numerical value. You would keep testing the loco by measuring across the wheels as you took it apart. As a TTS loco, the sound decoder will be using a 8 pin plug in socket, so this would be first component to remove to see if the 'short circuit' goes away. As components are removed and/or wires disconnected. Then whatever action you take that removes the 'short circuit' will start to focus the testing on what is causing the 'short'.

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If a 'short' does indeed prove to be in the TTS decoder, the loco would have to go back to the supplier anyway to arrange a warranty repair via Hornby or their service agent. As a 'short' in the decoder is unlikely to be something you could repair yourself.

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Sometimes with 8 pin decoder connectors. A 'short circuit' can be created if the plug is pushed too far into the socket (if there is an uninsulated  metal chassis component under it). Therefore, if removing the decoder plug removes the 'short', then check for any metal under the socket that might be too close.

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Given the complexity of the task, the need for a multi-meter tester and the skill to use it. Then my advice would be to send it back for a refund or replacement as it is a new purchase.

[96RAF]

If it's new and still under warranty I wouldn't fiddle with it but take it back to where you bought it from for them to fix, else you risk invalidating the warranty.

Rob

[Bill888]

I will take the loco back.  The Selector works fine with the other 2 locos in the Mixed Freight set so no problem there.

Many thanks.

Bill