Hornby Tiger shorting out DCC track

[Joshua-348227]

Apologies if this is the wrong forum for this question.

Fitted the sound decoder into the new Tiger and am having issues with it now shorting the DCC track. Track is wired up with droppers on all sections, no dead spots, correctly isolated and all other trains run perfectly.

Using NCE PowerCab as DCC controller.

Train power ups for a sec then dies, red light on controller plate goes off, remove train light comes back on.

What is most logical place to start ?

Thank you

[96RAF]

The decoder installation is suspect. Unplug the decoder and use a meter to check no unwanted continuity between socket pins.

[P-Henny]

The most logical methodology is to start with the loco and review your decoder fitting process.

Revert the loco back to DC by refitting the DC Bypass blanking plate (if originally fitted). Then test the loco back on DC. If you have access to a multimeter (I recommend you get one if you haven't already) then perform a stall test to see what the maximum current the loco draws on DC.

Knowing the stall current will be a good indicater with regard what to suggest next and where the cause of the reported issue may lie.

How to do a stall test is linked to in the 'Useful Links' sticky thread located at the top of the 'General Discussion' forum.

Doing a stall test IMO should be performed as standard before fitting any loco with a decoder. As well as checking loco functionality under DC Analogue control as a pre-requisite to decoder installation.

You haven't given any indication of decoder brand / model. Is it an 8 pin one. There is historic issues with some Hornby 8 pin sockets in the locos where factory errors short out pins 1 to 8 or pins 4 to 5. If these socket shorts are present then DC Analogue control is unaffected and the loco appears completely normal, but any decoder that is fitted is instantly damaged and could potentially cause a DCC controller to trip. Again, this is where access to a multimeter is crucial so that the 'resistance' meter function can be used to test for faulty socket wiring.

96RAF posted whilst I was typing mine. We are both basically singing from the same hymn sheet.

[Joshua-348227]

Thank you to you both. Should have said it is a Hornby 18 pin sound decoder and it is a tight fit in the tiger.

[5Dublo2]

Can't really help with Troubleshooting, but I have Tiger with a Hornby HM7000 fitted and use it with an NCE Powercab - no issues, which at least confirms that all the items are compatible with each other.

Please check the images I posted in this thread to see the installation (sorry you may have to manually copy and paste the URL as whatever I do with links on this forum never actually creates a working link)

https://uk.hornby.com/community/forum/hornby-lion-dcc-decoder-358812