Programming issue (Power cab and Tsunami)

[Runaway]

Got the transistor soldered and everything is good to go. I thought I would mention that even after I fixed it there is 0 volts DC showing on my digital meter when reading across the track rails. It was also this way before I fixed the transistor. In case someone comes looking for diagnosing info in the future, you are only going to see AC voltage. Mine shows about 15.7V checking in both directions after the fix.

[betamax]

This does make sense.  If one side of the output wasn't working, there wouldn't be a proper DCC signal on the track.  The decoder might work, but the negative or positive part of the signal is missing, making it impossible to drive the motor in one direction.

With just the positive signal, the decoder would probably power up.  It might even recognize the DCC signal and respond accordingly. Some decoders put the raw DCC signal right on the motor, switching the polarity accordingly. (That is why some buzz no matter what you do.)  It is possible that the Tsunami uses a positive and negative rail going to the motor controller.

[Runaway]

I just opened up the Power Cab and stumbled onto the problem. There is a small component labeled 2 F that was installed crooked and one of the 3 legs is just about .001 from touching the solder pad where it is supposed to be connected. I tested for continuity to make sure it wasn't connected. It wasn't. I shorted the leg to the solder pad with a precision screwdriver just to make sure that was the problem before soldering it and my loco worked correctly. Thanks for the direction CSX Robert. I probably wouldn't have found it if it wasn't for your idea about the H bridge. Now to find a low enough watt soldering iron with a tiny tip. Thanks again, and I appreciate all the help everyone offered.

[CSX Robert]

I didn't think of this earlier, but try measuring it with the meter set to DC.  If one rail is not working, then you won't have AC.

[Runaway]

I get 18.99 and 19.00 volts AC on the 2 rails when measuring both ways. That's with the red light on at the bottom, the Power cab plugged into the left port with the flat 6 wire cable and nothing on the track. One section of track.

[Runaway]

Thanks for the info. I'll measure it when I get home today. I really hope it's not the Power cab but at this point I just want it fixed. The loco is already going back so the Power Cab might as well be fixed at the same time if it needs it.

[CSX Robert]

Runaway

If one side of the h bridge wasn't working wouldn't one of the track rails be dead?..

Not necessarily, it could be stuck at one potential or the other.  Normally, on most DCC systems, the output to each rail switches between positive voltage and ground.  When one rail is at positive, the other is at ground and vice-versa. If one rail is stuck at one potential, the decoder will still get power because of the other rail switching, but it will only be half of what it should be(it will actually get full power, but only half of the time).  Most decoders detect the DCC signal by monitoring only one of the rail inputs to the decoder.  If the rail that the decoder is monitoring is stuck at one potential, then the decoder won't see the DCC signal.  If this is the problem, if you check the voltage with a voltmeter, it should read about half of what is expected.

[Runaway]

If one side of the h bridge wasn't working wouldn't one of the track rails be dead? I have a psx-ar reverser but this problem occurs even when only using a single test track, not just on a full layout.

[Runaway]

Sorry. Hit post before I was finished typing. 

[CSX Robert]

It sounds to me like one side of the H-bridge that drives the track output of the Power Cab might not be working.

[ba&prr]

What type of auto reverser do you have for your reverse loop?  Joe

[Runaway]

This makes more sense than anything. It is a factory installed decoder, so hopefully Athearn will take care if it. It's brand new.

[betamax]

Since DCC has no means to control direction using track polarity, something is really wrong.  There might be a wiring error, or the motor hasn't been disconnected from track power.

Maybe a trace hasn't been cut that should be?

[Runaway]

This is currently my only dcc loco. The led is still lit when I turn it around. Same problem with a single piece of track.

[woodone]

If the OP can run the loco one way I don't see how he has a track power problem.

OP,do you have a second loco to test with?

When you turn the loco around do you still have the power LED showing on? (The red LED on the panel)

Do you have this problem on a single piece of test track ( just a 2 foot section would work)

this will make sure you don't have some problem with your layout.

[Runaway]

My loco will run forwards and in reverse just fine as long as it is pointed in one certain direction. Which direction depends on which rail I have each wire connected to on the 2 terminals on the panel. Everything works perfectly as long as I don't physically pick up the engine and point it in the opposite direction. If I do that, I have to reverse the 2 wires that go from the panel to the rails otherwise the loco will not respond to any commands. I can also run the loco through a reverse loop and when it comes back on the main I loose all control which is exactly the same as reversing the 2 track wires or physically pointing the loco in the opposite direction. I am now having issues with one of the ditch lights as well so I think I'm going to return the loco to Athearn and have them check the decoder out while they fix the ditch light. This thing acts just like a dc powered led. Works with one polarity and not the other. Since its not a dc setup, polarity shouldn't make any difference. I'm at a loss. Hopefully Athearn will find the problem. I don't have another dcc loco to try to narrow it down.

[cacole]

Re-reading your original message, let me see if I'm understanding it:

1.  You say the locomotive will run in one direction (forward?) but not in the other direction?

2.  When you physically turn the locomotive around  it won't run at all?

If that's what you're saying, it sounds like you don't have the Power Cab connected to the track correctly through the small panel that NCE provides.  Double-check your connections to the panel from the Power Cab, and from the panel to the track.  

Are you using the FLAT interface cable and not the coiled cord?  Do you have the Power Cab plugged into the LEFT socket on the interface panel?

Make sure you have the track wires connected correctly on the rear of the panel.  

If none of this solves your problem, you may need to email or phone NCE and see what they think may be wrong.

[Runaway]

I set cv29 to 34 but no change. I have reset the decoder as well as the power cab also with no change. I don't have any problem programming the loco address as long as the loco is pointed the right direction.

[woodone]

I have no idea has to why when you turn the loco around you have problems???

I would do a reset of the decoder first. C8 to 8 then remove the power to the loco. This will set the decoder back to factory defaults.

NOW with out the loco on your track, push the PROG/ESC button 4 times= display should read use program track- hit enter and the display will read 1=STD , 2=CV, and 3=REG,  NOW PUT YOU LOCOO ON THE TRACK.  push 2 for CV,display will read back the mfg ID # ??? hit enter and it will read back the decoder version #?? hit enter and it will read back set up ADDR,  hit 1 for yes, read back will ask address enter 1 for yes and you can enter any two digit address the display will then ask if you want to activate this address, hit 1 for yes FOR A 2 DIGIT ADDRESS  or just hit enter one more time and it will ask to set up a long address, enter any 4 digit address and enter, the display will then ask if you want to activate this address, enter1 for yes. Now you should have control of your locomotive via what ever number you programmed into the address. 

[Runaway]

I programmed it for DCC only using 0 for cv12. That stops the loco from taking off when turned around, but it still won't accept commands. I don't think it's a wiring issue. At this point I'm just using a single piece of track with the 2 wires from the Power cab connected to the 2 rails. I have also tried a small oval with only 2 feeders and all rails soldered. I'll try the 34 on cv29 when I get home.

[cacole]

Put the loco on the programming track and enter a value of 34 into CV29, and see if that corrects the problem.

Why it will not run when you turn it around doesn't sound like a decoder problem, but something else with your layout wiring.

[jeffrey-wimberly]

As for it just taking off in reverse, is the analog mode still engaged? If so the decoder needs to be reprogrammed to recognize DCC only.

[Runaway]

I guess, like many others, I found this great forum while searching for an answer to a problem. This seems to be a helpful group, so great to be here.

I have a new Power cab and a new Athearn Genesis loco with the Tsunami decoder. The problem is, everything seems to work perfectly on one heading, but if I place my loco on the track heading the opposite direction, I can't program it and it doesn't respond to any commands even if it is already programmed. When I place the loco on the track in this manner the sound starts and it immediately takes off in reverse. The problem with this is that my planned layout will have reverse loops and when the polarity (phase) shifts coming back on the main in the opposite direction I loose control of my loco. I have tried programming on a simple small oval and on just a short straight section using programming on the main and programming track methods. All of my equipment including track is new. I have never seen this problem and can't find anyone else who has either. If someone could shed some light I would be very grateful.