Minitrix BR260 broken??

[Dani]

Hello,

I have a very new Minitrix BR260, with 2 hour running maximum. It has NEM connector and I installed an Uhlenbrock decoder:



It's been working ok many times, but two days ago I saw it wasn't able to pull a lot of wagons, it was like loosing power progressively. Today it's not able to climb a 2% ramp without wagons!!!

I start loco, runs 3 cm. and stops, but I can hear the buzzing like when you give the minimum speed to a loco that still doesn't move.

I don't have other NEM decoder to replace, but I reseted it and seems to work well (function, read and write CV, ...). I also opened and cleaned loco, but with no better results.

Any idea?

Thanks in advance!

Dani.

[Bernard]

Dani - Have you tried running the train without the decoder installed? I've had a couple of problems like this and I decided to take the decoder out and try and run the train on DC, and what I sometimes find is a stripped gear or a worn down motor brush. (Check the seating of the motor brushes but be careful, they are small and easily pop out.)
Without the decoder the train should run fine (lose connection from the decoder, etc.) but if it's still having these problems that you've described it could need a new part....which shouldn't happen to a new train.

[Martijn Meerts]

Also, if you're up to it, try taking out the motor, and see if it runs smoothly without any load on it.

As for the NEM plug, many Minitrix trains have really bad connections from those plugs. I've had locomotive where the top part would just pop off the moment you tried to plug in a decoder.

[inobu]

Dani,

The advice given is right on and the discerning factor would be how much you trust your install.

Questionable install go with Bernard, good install go with Martijn.

The most effective method is to start with non intrusive evaluation (troubleshooting) working to intrusive. I've gone into decoders trouble just to find out my track was not terminated connected good. Sickening.   

Inobu

 

[Dani]

Thanks for all your answers!

I'll try to isolate the problem, but first I'll have to find a DC station. My old DC "central" is broken so I started directly with DCC instead of repairing it.
I read many posts about problems in NEM connectors in all Minitrix, but I guess if the connector was the cause it wouldn't run at all, not only few centimetres or very slowly... about installation, all other locos run very well and I soldered a feeder in each single track. As I work with long flex track segments, there aren't too much but more than the necessary to assure everything is well powered.

I'll follow your indications and post results again.

Thanks!
Dani.

[Dani]

Hi,

I did the tests:

* Replacing the decoder with the dummy and testing in DC the behaviour is exactly the same: At full power starts to run very slow and stops after few centimetres.
* Remove the motor and feed directly: Motor works perfect

So if it's not the motor neither the decoder, the problem is in between. And in between there is the worst design and concept I've ever seen in a loco. Now I love the KISS (keep it simple and stupid) philosophy of Kato!!!!

I try to explain: Decoder is plugged in a small circuit that also has a reel and some more elements. This circuit has a wire to feed the positive from the wheels, and it has no black wire to feed negative  Finally I saw negative current is taken from the screw used to fix this circuit. This screw is in touch with a metallic part of the chassis, and that last is in contact with the other side of wheels. And even worst, the motor is soldered with a wire to this circuit (negative), and positive is taken by contact with this circuit.

So there are so many things that can fail in the design, that I will remove that circuit and solder a wired decoder directly to the motor and wheel feeders, as I do with Kato locos.

[Martijn Meerts]

Minitrix is real good at coming up with complicated designs ;)

If the motor runs fine, but the train still runs bad even on DC with the original board in it, there has to be something binding the wheels. Do they run freely without the motor? I've had Minitrix trains cause problems because the tiniest spec of ballast had lodged itself on a gear. It was so small it was barely visible, and definitely wouldn't have caused any Kato/Tomix/MicroAce to react like the Minitrix did ..

[Dani]

Problem solved!!!

I removed all wires and electronics from Minitrix and soldered a NEM connector. I plugged an Uhlenbrock decoder and Rei Chan confirmed everything is working OK now.



Thanks!

Dani.

[Martijn Meerts]

Just goes to show (yet again) that the minitrix NEM sockets are a load of junk ;)