Hi all,
Just wanted to share, that last week we had two incidents of Bachmann decoder malfunction, which caused the PWB to burn and char my carpet. Fortunately, me and my wife were at the layout both times and didn't leave the room to pour some coffee or use the bathroom.
The first event was caused by sloppy winding and packaging of one of the solenoid coils, causing opposing ends of the coil to press against one another in perpendicular direction. Eventually, the thin coating on the wire gave in to pressure of the tight enclosure, and boom. The 50 mA output circuit had to handle 0.8 Amp, which it obviously couldn't.
We were lucky to catch both events in the making, however, we don't want to face the future when its not safe to turn your head away from the running layout. And my wife said, no more Bachmann in our house. I already opened and tidied up all the coils and I'm facing pending work of replacing all 8 Bachmann decoders.
Just wanted people to know about our experience. If anyone wants to know more detail, I can provide. Just reply to this message. Best regards,
Andrew

Hi all, I'm using bachmann DCC #6 crossovers with powered frogs. I'm also using electrical pickup trucks to add lighting effects to the rolling stock. Everything works all right until a mistake happens in operating the crossovers when the trains are running over. I understand that this causes various types of shorts, but this isn't the problem.

The problem is that the crossover decoders are vulnerable to the electrical transition currents and can get stuck in a certain position, and won't respond to throw/close signals. I did some troubleshooting and ruled out loco decoders; types of electrical pickup trucks and the DCC system. I suspect that the problem is that the decoder memory gets altered and it looses the address that was programmed into it. It is easily fixable by taking the crossover out, reprogramming the address and putting it back. However, its a hassle.

Has anyone come across this defect? Any recommendations how to improve the decoder protection from such spikes and transition currents? Thanks...
Andrew
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Update of Apr 27.
Upon further research it was discovered that Bachmann uses in their decoder a cheap knock-off of the venerable 12F629 controller, and they didn't implement the manufacturer recommended noise protection circuitry. Nothing can be improved here, except unpowering the frogs (not a guaranteed fix) or replacing the decoder with a different brand.
I think I'll go with the latter.
Andrew