Digitrax DN163K1C Problem in Kato SD70ACe

[wmcbride]

I have a DN163K1C decoder installed in a Kato SD70ACe which, when the track is powered, runs backwards.

The decoder does not respond to addresses such as the engine's four-digit road number, the last two digits of the road number, or "03."

When I tried to reprogram the road number on my programming track (Digitrax Radio Chief) all I get is no response which indicates an electrical contact failure between the chassis and the board; or does it? I checked and it sure appears that the decoder is in contact with the frame.

I tried to do a factory reset of the decoder per the Digitrax pamphlet that came with the decoder to no avail. I do get headlight flashes: 1 quick followed by two quick flashes'

Anyone have any suggestions?

[peteski]

What do you mean "when the track is powered".  You mean trying to run under DC (not DCC) power?  Backwards as relating to what?

Couple more comments:  In this installation, the decoder has copper tabs which contact motor leads.  Assuming that you made sure that the motor leads are tucked under those copper tabs then there really isn't anyway that the motor leads could be shorting to the chassis.

[wmcbride]

Thanks for your response.

Under DCC the engine is running in the reverse direction. It's as if the decoder has been set with a reverse throttle setting which I cannot change. That's why I thought a factory reset would be the solution.

All the contacts look fine including he motors leads. This is one of nine Kato SD70ACe's I have, all with decoders (either TCS or Digitrax).

I think I may have to take the decoder out and reinstall it and see if that helps.

[peteski]

Thanks for your response.

Under DCC the engine is running in the reverse direction. It's as if the decoder has been set with a reverse throttle setting which I cannot change. That's why I thought a factory reset would be the solution.

All the contacts look fine including he motors leads. This is one of nine Kato SD70ACe's I have, all with decoders (either TCS or Digitrax).

I think I may have to take the decoder out and reinstall it and see if that helps.

Now I'm even more confused. How can you run the engine on DCC if you don't know (and can't set) its address?  Ignoring that fact, what happens if you change the direction on the throttle? Does it run in the other direction?

If the decoder (and all its functions) were running ok then I would suggest taking the model apart and turning the motor 180 degrees - that would reverse its polarity (and direction).

[ednadolski]

This is one of nine Kato SD70ACe's I have, all with decoders (either TCS or Digitrax).

If you swap the decoder in the troubled engine with another one from a working engine, does the problem follow the decoder or stay with the engine?

Does the engine run OK on normal DC, (with the factory circuit board)?

Ed

[John]

first, clean the wheels, all the contact strips, then re seat the decoder in the loco .. after that, try to issue the digitrax reset command on the programming track ..

[woodone]

Did you install the Kapton tape per the instructions where the motor leads are. The side wings can touch the frame in these locations.
The next thing is making sure that the decoder is making good contact to the frame at the front. Sometimes you must wedge a small piece of foam between the frame and the board to get the board to make good contact. 

[wmcbride]

Thanks, everyone, for your advice.

The decoder had worked in this engine earlier (run for about 20 minutes after installation and then laid up in  the box for about a year. I installed the decoder using with Kapton tape in the recommended places and I put the small piece of foam under the front of the board to ensure electrical contact as was recommended when these engines first came out.

When I put this engine on the track it just started moving in the reverse direction at a constant, moderate speed. It was as if it was following the last speed and direction command the decoder had received. For most engines, I program the four-digit road number as their address. I checked and checked again trying to run it under the four-digit address, under the last two digits of the road number and as default address of "03." No change.

I put it on the programming track and tried to program a two-digit address and received a "NoAk" message.

Since my last posting, I have taken the decoder out and observed some slight "grooves" on the contacts indicating the frame has been making good electrical contact with the decoder. The contacts were all clean and Kapton tape intact. I reinstalled the decoder and tried to run it. Nothing. I checked the contacts and everything looks ok. I physically fiddled with the decoder and then put the engine on the programming track. I tried to program an address of 03 and got a NoAk message and one flash followed by 3-4 quick flashes on the decoder's SMDs.

Tomorrow I will take the decoder out and try another decoder in its place and see. I will also shift this one to a "good" SD70ACe and see what happens.


I think this decoder is not healthy and maybe I killed it.

[wmcbride]

Tonight I put this engine on the mainline after checking the motor contacts were making contact etc.

I tried address "03" and nothing forward. Then I hit the reverse direction button and the engine went in reverse and was responsive to the throttle. I then selected the forward direction and the engine will not move.

Both forward and after lights respond to F0 and are directional (the rear SMD turns off with forward direction selected and the rear SMDlights up, and the engine responds to the throttle, when the engine is moved in reverse.

I tried to do a factory reset using CV8 to no avail. I got a NoAk.

So this is working OK -- as long as I want to drive in reverse...

[peteski]

Tomorrow I will take the decoder out and try another decoder in its place and see. I will also shift this one to a "good" SD70ACe and see what happens.

Did you try what you mentioned (above)?  That should confirm whether that decoder is fried or not.

[wmcbride]

The next step is a swap out. I just ran out of energy last night.

It's all voodoo anyway... 

[peteski]

The next step is a swap out. I just ran out of energy last night.

It's all voodoo anyway... 

...and smoke & mirrors.  Well, until you let the magic smoke out - then things don't work anymore. 

[wmcbride]

I cooked an LED the other day. Ugh! What a smell.

Decoders tend to be pretty inoffensive when I kill them...