Gs4 Kato dcc problem

[Viperjim1]

I have a dcc Ito GS-4 that had the retro kit done to it me it won't run. I took out the decoder and tested on my program track and it read manufacturer code and decoder version or code and put it back in the loco and it came up cannot read decoder. I'm using an NCE power cab. I retested the decoder out of the loco again and still could not read so I purchased a new decoder and still came up cannot read so profaned on program track and did decoder rescue or something like that and as it went thru all the cv's it moved very minutely and when program rescue stopped so did the loco. It reads the manufacturer and all that but will not respond to throttle increase. Any ideas? Thanks in advance.

[mmyers]

What address are you using? NCE can run a short address as a long address. How is it programmed? e.g. 0034 is a long address, 34 is a short address. Depending on CV29's setting, only one will work. also check CV19 to be sure it is 00.

Martin Myers

[woodone]

I am guessing when you said it has the retro kit you were talking about the plastic shims that you put behind the drivers.
I have seen this retro kit fail more times that I don't trust the retro kit. I isolate the motor 100% buy running wires from the decoder to the motor.
This loco has cost me more decoders than all of my other installs put together. I do DCC installs for a lot of people. Like in the 1000 range of installs.
So I would say remove the motor and isolate it. Then install a decoder and be done with it once and for all.

[Viperjim1]

Thanks so far for your help and I'll look into those ideas. Thanks

[Ike the BN Freak]

I'm having an odd issue where the loco seems to run fine in reverse, however won't run forward, however if I put the DC board in, works fine.

Thinking of just hard wiring a DZ123 in and replacing the EM-13

[woodone]

Is this a GS-4 also? If so same has I stated in my first reply. Sounds like you may have lost the forward drive transistor.

[Ike the BN Freak]

Is this a GS-4 also? If so same has I stated in my first reply. Sounds like you may have lost the forward drive transistor.

It is, however this is the first I've seen any mention of forward drive transistor. Guessing I'll need a new decoder

[peteski]

Just out of curiosity, try running it on DC (even if you have to take a piece of track and power it by using a 9V battery) and see if the decoder behaves the same way in DC. I'm assuming that the CV29 has the DC operation bit set (they usually do).

Decoders usually use an H bridge to supply power to the motor.  It consists of 4 transistors (one pair for forward direction and another pair for reverse).  If one or both in the same pair are blown then the loco won't run in that direction.

[Viperjim1]

This problem does not involve a decoder but in dc operation it moves slowly in forward and great in reverse any ideas? Thanks

[peteski]

This problem does not involve a decoder but in dc operation it moves slowly in forward and great in reverse any ideas? Thanks

I think maybe we still need to clarify the problem description.

I'm surprised that you were able to access and read the standalone decoder on the programming track. Usually the decoder needs a load on its motor or function outputs (like headlight light bulbs or LEDs) in order to acknowledge programming commands from the command station.

What brand/model decoder is it?

Is the problem present (slow forward normal in reverse) even with the decoder removed in DC operation, or only when the decoder is installed and it is running under DC power?

If the problem occurs in DC without a decoder installed, then it is most likely a mechanical problem.

[Viperjim1]

Yes there is no decoder involved. And runs about half speed forward but runs regular speed in reverse, meaning fast in reverse and slow in forward, about half as fast.

[Viperjim1]

This is a completely different GS-4 not converted yet.

[peteski]

LOL, that wasn't obvious at all. Right in the middle of the thread, you switch locos!  One loco per thread please. 

And you are sure that the throttle running the (second) loco is working properly? If you used it with other locos they behave correctly?

Is there any noticeable noise difference between the loco running forward and backward? 
Does it seem like the loco is laboring hard when running forward (like it is overcoming large amount of friction?

[Viperjim1]

no runs smooth both directions, and no noise but slower forward than reverse. going to take the shell off and check the drive.
but the other one with the dcc problem, it was the tender contact, not fully seated , fixed and runs excellent.

[Mike C]

Maybe you could adjust the forward trim CV ?