HELP! DCC loco causes short circuit only when power is applied to move the loco

[JeffPreston]

Hi all:

I wonder if anyone can help?

I was running some trains yesterday when all of a sudden, my Farish WD stopped and the NCE Powercab handset displayed the reset process which it always does when a short circuit occurs.

I took all (3) locos off the track and shut off the power at the mains. Turned the NCE Powercab back on and tested another loco - all fine. Tested a 3rd loco - all fine.

I put the Farish WD on the track - and no short circuit.

But... if I apply power to the Farish WD - I get a short and the NCE Powercab resets.

I took a look at the Farish WD and can see no obvious flaw, so I gave it a good bit of TLC to remove any loose bits of rubbish - and still it shorts - but only when power is applied.

I figure the DCC chip could have failed in some way or there could of course be something deep down inside the loco which is causing a short?

I am not a skilled jeweler, so the brute force approach of stripping the engine down to its molecular form, cleaning and rebuilding it is something beyond me, but I was wondering what the recommended next steps might be?

The loco has run fine for months, but has only a total of about 2 hours of running under its belt, as does its installed chip.

I don't have any spare chips lying around - but can of course put the blanking chip back in and test with simple DC power.

As in the real world, funding is tight for this railway and I don't want to buy another chip right now if I don't have to.

Any ideas and tips are much appreciated! Thanks to all.

[Newportnobby]

I don't have any spare chips lying around - but can of course put the blanking chip back in and test with simple DC power.

That would tell you if the loco is OK at least.

[cjdodd]

Blanking plate in first and test of DCC that way you know the loco is ok.

THEN pull the DCC chip from another loco and test it.

If you swap the DCC chip for another one without testing with the blanking chip first then you risk ruining another chip.

[JeffPreston]

Thanks everyone!

Oh boy - does not look good.

I put the blanking chip in and tested on DC. Nothing at all. I tested DC system with a (different) DC loco to be sure and it ran fine.

There appears to be a small black/melt looking dot on the DCC chip I took from the Farish WD.

So at this point we don't know for certain if the chip is ready for the bin, but we do know that the Farish WD will not run on DC.

I hope it is still under warranty. I've hardly ever run the thing since I ran it in on DC and then put the DCC chip in. Thinking about it probably 2 hours run in with DC and then 1 hour DCC running since.

[JeffPreston]

Yes it is a Bachmann chip and sadly I bought 2 without knowing that they have a bad reputation in some quarters.

One died some time ago in a different loco. Also has melt mark on it.

The warranty on the loco is 12 months so I am out of luck there.

Bought all from Hattons in FEB 2014.

[Sprintex]

unfortunately those blue bachmann chips dont have a goof proof warranty like the dz126 ones from digitrax have

Or the TCS ones I use for my entire fleet, BECAUSE they have the goof-proof warranty


Paul