Wierd ESU loksound motor problem

[kwledbetter]

OK need some help to start troubleshooting.

I installed a loksound micro4.0 into an n scale bachmann 611.  I have done several of them leaving the original board in as it's "DCC ready" but it always bothered me that that board took up so much room.

Stepback i first tested the loco in DC when I received it and it worked fine.

So long story short, I removed the board.   make sure I traced out the pin connection to the loco and then rigged up the decoder in the tender with a 1k resistor to the reverse light, a yellow light to simulate the firebox and the wire going to the headlight.

Good news.  The firebox, reverse light and sound are awesome.

When I try to go forward nothing happens. Well  I won't say nothing, the sound thinks I'm going forward and chuff increases etc but no loco movement.  Reverse seems fine but when I stop from reverse it still creeps backwards.

I checked the wires that go to loco again and no shorts.  Should I redo the connections to the headlight and motor wires just to see or what is the best way to begin to troubleshoot.  Really hoping decoder isn't bad because sound is so awesome and I spent a lot of time on this one.

HELP!!!!!!!!!!!  I can take pics or video if helpful and have a good multimeter and even a oscilloscope on breadboard so suggest away.

[Steveruger45]

What decoder model is it?  And yes photos may help.
I’m sure Peteski could help here,  but if all the wiring and soldering is good it may be a problem with the H bridge on the decoder.  I’ve had that on one 73100 decoder where it would go one way but not the other and that was the issue.

[peteski]

Yes, what decoder? Is it a known good decoder?  Also make sure no part of the decoder's circuitry is exposed and touching any metal parts of the tender?

I would unsolder the motor wires (orange, gray) from the decoder, to isolate the motor from the decoder, then try to run the motor by hooking either a DC throttle output or a 9V battery to the motor leads.  See if it runs the same speed forward and reverse.  If it runs, then we know the motor and its leads are correctly identified and the problem is with the decoder.  Your description does seem to be indicating a problem with the decoder.  But maybe the motor wiring harnes is shorted to seomtghign else in the model.  If you have a multimeter handy, since you already usoldered the motor wires you might as well make sure that they are nto shorted to any of the other circuits in the model.  So measure the continuity between one of the motor leads wo all of the other wires in the harness. DO the same for the other motor lead.  There should be no continuity or a very high (infinite) resistance.

[kwledbetter]

So it's a 54800

Good suggestions and appreciated. I'll do that and troubleshoot some more tomorrow and report back.

[Mark5]

Following this as I have two of these Js with the crappy motors.

[kwledbetter]

Not to derail to much but I picked up 5 of them for $70 each  brand new last year.  I have 2 of them that I installed dcc (one a zimo sound, and one a lokpilot)  This was my 3rd and first attempt at removing the original PCB.

[kwledbetter]

Didn't have much time.  I did pull everything back out and crack pins with multimeter etc. And all looks ok.  I did not have a chance to test the motor or desolder the leads yet to do that bit.   Its looks a little raffled here as I had it all tacked down nice and neat but wanted to test etc so ignore the resistor where the heat shrink is not big enough etc.  It was all well protected with zero metal exposed.  Also you might be able to see where I ran wire and soldiers the front and rear pickup together.  Ignore the fact the wire color is wrong there.
It's only the connecting wire.  The wires ro the decoder are opposite and correct. The shrink tube on the decoder itself is down further then I've seen so many there is some minute chance that touched but how I had it in there I highly doubt it.

I'll unsolder and do the motor testing when I get a chance but will probably be next week.

[Steveruger45]

On the first photo, Is that a solder bridge on the decoder bottom two pad connections?  It may be just a reflection though.

[kwledbetter]

I am officially an idiot.  Got some time this afternoon and before I unsoldered from the decoder I decided to look at everything one more time.  Well I'm glad I did.  I took the cover off the loco and low and behold the pinout was different then the other 3 I worked on! Quick switch of the blue and grey wires on the tender connection and all great now.  Like I say I feel dumb but do appreciate the help and suggestions greatly!

[Steveruger45]

Glad you found it.

[peteski]

Excellent!  Can't trust anybody anymore.    Also lucky no magic smoke was released due to the mis-wiring.

[kwledbetter]

Totally agree.  This mistake though stupid is much better (and cheaper) than a magic smoke mistake!

Been running it around this afternoon and it's awesome.  If anyone has one strongly recommend this speaker option!  I used the Streamlined backshop sound file for the 611 so about as prototypical as you can get.