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DCC issues with two locomotives with Digitrax Decoders Track and electrical/DCC
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New member 5 posts BigJoe6401 New member 5 posts
BigJoe6401

I was cleaning the wheels on two locomotives (N scale).  One was the Atlas GP-38-2 and the other was the Kato F-7A.

On the Kato F-7A, after I cleaned the wheels.  I tried to play with the speed matching values, but no luck.  It would not start off until after 57 on the DT402R throttle.  Then it did not run at all.  I managed to reset everything.  It works no on address 03, but I cannot program the unit number, speed table, or anything.  The message comes up with "No AK", which means the decoder is not acknowledging the address or any changes.

Same situation with the GP38-2, but I did not try to play with speed matching (I already learned my lesson from the F-7).

These decoders are old (the F-7 I got in 2006, the Gp38-2 was not that long ago, say 2011?) so I wonder if the decoder is the issue.

An Atlas forum mentioned a possible answer for the No AK message as checking the contact strip or something like that.  I think the 38-2 is okay with the contact strip matching to the frame, but not sure if any of the contact strips somehow got loose where the motor tabs contact the decoder.  Not sure about the F-7A.  Too intimidated to try to take the shell off fearing breaking the coupler cover and seeing the front coupler assembly fly into the dark vastness known as a black and brown mix colored rug.

Any help is appreciated.  Thanks for the long read.

 

 
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Lee1234 Active Member 73 posts
Lee1234

You are not getting a

You are not getting a connection to the decoder.  I would review what you did when you cleaned the wheels.  If you are worried about parts flying away work in a shallow box on a bench or table.
L
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Russ Bellinis Prolific poster 3,335 posts
Russ Bellinis

I think Atlas uses wipers on the wheels to pick up power.

I model in ho, not familiar with N scale, but ho Atlas locos use wipers on the wheels to pick up the power from the rails.  If the backs of the wheels or the wipers are dirty or are not making contact, you will have problems getting power to the decoder.  Regarding the post above about a shallow tray for working in, a large metal cake pan for making a sheet cake might be perfect, probably 12" x 18"-24" rectangle.
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BigJoe6401 New member 5 posts
BigJoe6401

One of my friends stopped by

One of my friends stopped by the hobby shop this past Sunday.  He was able to reprogram the F-7A, but was not able to work on the GP38-2.  He took it apart and hooked up a 9 volt battery to the motor and the motor worked, so it was the decoder.  I bought a new decoder and he installed it and it works now.

Thanks for the replies.  I do have a foam cradle to use to hold the pieces in, but with my big fingers, I'm too afraid to play around with them.  Since I do have some older locomotives, I may be able to work with them to get the feel of taking them apart even though they are not DCC (and screaming to me to get the TCS CN and/or CN/GP decoders).

 
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