Tsunami decoder strange behavior

[Dave V]

One of my Blackstone K-27s is misbehaving.  It still has the factory-installed Soundtraxx Tsunami.  I plan to call Blackstone tomorrow and I fear the worst, but it's a strange, strange error.  The locomotive works fine all all respects *except* if power is applied when it's in reverse.  When that happens I get a chirping buzz and the headlight flashes Error Code 12, which should indicate a motor overload fault...but I still get the same chirping feedback in reverse when the locomotive is removed and the tender is set out by itself!  Plus, like I said, it works in the forward direction just fine.  I reset all my CVs to default (sadly...because I had all the DDEs tricked out)...but the error persists.  Thoughts?  Advice?

[peteski]

Not sure if I understand.  By "power applied" do you mean DCC track voltage?  And reverse means that the DCC throttle with that locos address dialed up is at speed step zero, but with reverse direction?  What DCC command station are you using?

So, you place your model on unpowered piece of track, have the throttle dialed up to the loco's address, speed 0, and reverse, then you connect the track to the track output of the booster and it chirps with error 12?

You said that the loco works fine in every other aspect.  So all the functions work and it runs fine in forward direction?  So what happens after you run the loco forward, then stop it, change the direction to reverse and then try running it in reverse?  Does that work?

Call me confused. 

[Dave V]

Not sure if I understand.  By "power applied" do you mean DCC track voltage?  And reverse means that the DCC throttle with that locos address dialed up is at speed step zero, but with reverse direction?  What DCC command station are you using?

So, you place your model on unpowered piece of track, have the throttle dialed up to the loco's address, speed 0, and reverse, then you connect the track to the track output of the booster and it chirps with error 12?

You said that the loco works fine in every other aspect.  So all the functions work and it runs fine in forward direction?  So what happens after you run the loco forward, then stop it, change the direction to reverse and then try running it in reverse?  Does that work?

Call me confused. 

OK, call me confused too...

1)  OK, by "power applied"--and I realize that terminology is important and clearly I misspoke--I mean if I dial up a speed above zero in the reverse direction.  It sits with track power quite happily to go through its automatic random sounds, and if you apply a "speed" to it in the forward direction, it does exactly what it's supposed to.

2)  If it's running in forward and you hit reverse, she stops, makes her chirps, and flashes her headlight 12 times.

3)  If I turn on track power with the loco selected in reverse, yes, we get the flashes, but she tries to run in reverse with a strange stuttering 1/8th-turn-then-stop-then-another-1/8th-turn...

4)  And..................it's gone.  Tried to reproduce the error but I let the magic smoke out.  The acrid smell of toasted electronics.  Yay.

So...  A guy on one of the HOn3 Facebook pages has an old one from when he upgraded to a Loksound so he said he'd send it to me.

[peteski]

Ah, that is a better explanation, and oh well, the magic smoke is out.  It appears that the H-bridge transistors (motor driver circuit), or the low-power circuit that drives them might have been damaged.  I don't think you hastened the demise of that decoder - it would have happened eventually.

If you like, you could send that toasted decoder to me to add to a growing pile of fried decoders I accumulated, on which I'll try to do a post-mortem eventually. But not for a while.

[MK]

Peteski the decoder mortician! 

[peteski]

Peteski the decoder mortician! 

CSI . . um,  DFI (Decoder Fault Investigator). 

[MK]

On the next episode of CSI: DCC SVU