Tsunami TSU-750

[Geared Steam]

Hi guys

I recently installed an TSU-750 into an HO Scale Bachmann Shay, all went well as I

spent the last

several evening tweaking the CV's to more prototypical operations. Once I have this

completed

I latched onto 8 ore cars and started up the grade to check performance. After

several test runs,

the loco stopped moving in the "forward" direction, reverse still works fine.

After disassembling to check gears issues, I discover all is well with those but

the motor

is not getting power from the decoder on forward, only in reverse?

(The sound continues to work normally) This eliminates wiring issues, so

it has to be the decoder. Did I damage the forward drive? Possibly to high an

amperage going through the decoder? It did not shut down from overheating,

and I have the decoder glued to the tender to use as a heat sink. I also

performed a decoder reset with no results, same problem.

Before I remove it do you have any recommendations? Maybe a 

CV being programmed incorrectly to cause this?

 

Any help would be appreciated, and thanks in advance.

 

(Edit- fixed the post so it's readable)

 

[tstage]

GS,

Did you copy & paste your post from another program?  It appears truncated on the right margin; enough so that it's difficult to "fill in the blanks" between lines.  Other posts I've viewed don't seem to have this issue.

Tom

[Geared Steam]

Thanks Tom, yes I did, thought I had fixed it. 

[PennCentral99]

Which wheelset did you attach the pick up wires?

Geared Steam

Hi guys

I recently installed an TSU-750 into an HO Scale Bachmann Shay, all went well as I

spent the last

several evening tweaking the CV's to more prototypical operations. Once I have this

completed

I latched onto 8 ore cars and started up the grade to check performance. After

several test runs,

the loco stopped moving in the "forward" direction, reverse still works fine.

After disassembling to check gears issues, I discover all is well with those but

the motor

is not getting power from the decoder on forward, only in reverse?

(The sound continues to work normally) This eliminates wiring issues, so

it has to be the decoder. Did I damage the forward drive? Possibly to high an

amperage going through the decoder? It did not shut down from overheating,

and I have the decoder glued to the tender to use as a heat sink. I also

performed a decoder reset with no results, same problem.

Before I remove it do you have any recommendations? Maybe a 

CV being programmed incorrectly to cause this?

 

Any help would be appreciated, and thanks in advance.

 

(Edit- fixed the post so it's readable)

 

 

 

This is a longshot; but, if the grade is enough to cause the tenders wheels to lift of the track from the downward pull/weight of the ore cars, thus a reduction in current, could it cause this? and the capacitor has a reserve to still maintain sound?

[Geared Steam]

PC

The loco works in reverse, but not forward. Flat and level with no cars. I have confirmed the decoder is not sending power to the motor in forward, but it is in reverse ( the motor turns)

sent an email to Soundtraxx, no answer yet.

[jrbernier]

  I suspect the forward motor driver circuit is burned out.  What was this "glue' you used to attach the Decoder?  Does not sound like heat sink gel.  

Jim

[richg1998]

Geared Steam

PC

The loco works in reverse, but not forward. Flat and level with no cars. I have confirmed the decoder is not sending power to the motor in forward, but it is in reverse ( the motor turns)

sent an email to Soundtraxx, no answer yet.

 

I had that happen to a SoundTraxx decoder, TSU-1000, not the 750 though. Sent it back for repair. Driver circuit for one direction.

Some years ago but I recall normal running and motor DC current was about 500ma. No possibility of shorts with the wiring in the loco.

I had done a decoder reset also. After reset, ran fine on address three in one direction and not the other. Wiring was fine. Verified with meter and a decoder tester.

The only issue I had with a 750 was the overheating issue, well known issue with this decoder.

As an aside, this overheat issue was discussed a lot with solutions in the Yahoo SoundTraxx DCC Group.

Also, a quick short will smoke a circuit in the blink of an eye.

Rich

[Geared Steam]

Thanks Rich

As I suspected, I'll send it in. 

[woodone]

It does sound like you have lost the forward drive transistor.

I would look very closely at your wiring- MAKE sure that you do  not have a part of the frame that could be touching the motor out puts! I have seen the TSU-750's over heat. Most times the overheating will just shut down the decoder. A motor to frame short will tsake out the drive transistors- also the ealier TSU-750's had an interninal fuse and you could have blown it. Check the wiring!!

[hon30critter]

Geared Steam:

Did you test the motor draw when stalled before you installed the decoder? I believe the TSU-750 has a maximum draw limit of .75 amps. If you didn't test the draw I suggest that you don't re-install the repaired decoder until you do so. The added load of the eight cars could have been enough to cause the motor to exceed the decoder's capacity.

Dave

[richg1998]

From what I know of the loco, it must have been a weak component.

Sounds like the installation was done and no wires dragging anywhere.

SoundTraxx changed their decoder selector page and I think the 750 was recomendedfor the Shay and Climax.

Rich

[Geared Steam]

Dave

It crossed my mind , but past experience with this model decoder in a Bachmann Shay and have had no issue, as Rich mention, Soundtraxx recommended this model for this loco years ago.

I haven't heard back from Soundtraxx yet.

[hon30critter]

Geared Steam

It crossed my mind , but past experience with this model decoder in a Bachmann Shay and have had no issue, as Rich mention, Soundtraxx recommended this model for this loco years ago.

OK, if Soundtraxx recommended the TSU-750 decoder than you should be OK. However, for peace of mind (mine if not yours) why not make sure. It is possible that your Shay isn't running right causing it to draw too much current. It's your choice. Do a five second test or maybe re-fry the decoder. What's to lose? Humour me!

With all due respect,

Dave

[rrinker]

 Definitely give it a test before putting a replacement decoder in. It could be a defect in the motor - a shorted winding or somehting, causign it to draw more current then it shoud. Or a slight bind in the forward direction. The problem sure sounds like one of the forward drive transistors is blown. It may just be a mater of time before a reverse one blows too, or it could be it was a borderline component on the decoder. FOr peace of mind (and to save further frustration) it is definitely worth testing out the loco, if just to eliminate a possible loco fault.

                            --Randy

 

[Geared Steam]

Props to Soundtraxx, they replaced the TS-750 with the failed motor drive with a Tsunami 2 TSU-100 all under warranty. Great customer service as always.

[PennCentral99]

Glad to see you got your issue resolved. Soundtraxx is usually pretty good to work/deal with.

[DigitalGriffin]

I would send it back for service.  Sometimes bad stuff happens.  The upshot is they might give you an economi which is better rated for the current.  Soundtraxx is pretty good with their service dept.

 

  Edit: I see they fixed your issue.  Good customer service as usual.