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Problems with NCE decoder

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  • Member since
    April 2013
  • 123 posts
Problems with NCE decoder
Posted by hustle_muscle on Friday, November 1, 2013 6:19 PM

A couple months ago, I put an NCE P2K-SR decoder in my P2K GP30 and put 2 LED lights inside it. I've noticed that even though I followed NCE's directions on the decoder (putting electrical tape between decoder and frame), the locomotive runs fairly jerky as if there's a short somewhere. How can I fix this problem and get it running smoothly?

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Posted by richhotrain on Friday, November 1, 2013 6:27 PM

There are some interesting points in the comments that you made.

One is that the loco has been converted to DCC a couple of months ago.  Has performance been fairly jerky ever since?

Two is the observation that there may be a short somewhere.  Based upon what?  The fact that performance is fairly jerky?

Are the LED lights working?  Is there power from both the front and rear trucks?

Tell us more.

Rich

Alton Junction

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Posted by Soo Line fan on Friday, November 1, 2013 6:36 PM

Questions and more questions. Smile, Wink & Grin

Did you pull the 6 diode  lighting  board ?  Did you hard wire or use the OEM plug ?

Jim

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Posted by hustle_muscle on Friday, November 1, 2013 6:37 PM

Sorry I made it a little vague.

The LED's are working just fine. The loco has been jerky since I installed the decoder (ok, the jerkiness has now gotten annoying) . As far as connections go, they look ok. I'm not sure if the jerkiness is from something electrical or if something else is affecting the way it runs.

The loco was DCC ready and I plugged the decoder into the plug included. I moved that piece up a little ways so there was room for the wires on the LED's (LED's are 3mm ones from Evan Designs and the wires are really long).

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Posted by richhotrain on Friday, November 1, 2013 6:50 PM

OK, I assume then that the loco ran smoothly before conversion to DCC.  Is that correct?

I have the P2K in four of my diesels, two GP9s and two GP18s and they all run fine.  That is a pretty reliable decoder.

Check to be certain that the decoder is fully seated and that none of the 8 pins are bent.  I am mildly concerned since you mentioned that you "moved that piece up a little ways".

Also, in reading the decoder installation instructions, NCE says, "In the GP7/GP9/30/SD60 remove the two screws holding the existing PC board, discard the PC board and replace it with the P2ksr decoder. Do not use the two screws to mount the decoder. The body shell will center the decoder on the frame. Caution: to avoid short circuits place a piece of  ELECTRICAL TAPE on the bottom of the decoder to insulate it from the locomotive frame.  Also, make sure there are no pinched wires between the decoder and frame or between the decoder and connector pins".

Check that out as well.


The instructions go on to say, "Test the locomotive before replacing the body shell.  Double check your wiring to make sure the motor is fully isolated and that there are no pinched or broken wires. We see many decoders returned due to wires getting pinched between the body shell and frame causing shorts".

Any pinched wires?

I wonder if the problem is that the decoder board is not firmly seated.

Let us know.

Rich

Alton Junction

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Posted by cacole on Friday, November 1, 2013 7:19 PM

Did you solder the wire connections to the truck pickups and decoder instead of using those plastic clips that work loose and cause erratic contact?

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Posted by Soo Line fan on Friday, November 1, 2013 7:44 PM

cacole

Did you solder the wire connections to the truck pickups and decoder instead of using those plastic clips that work loose and cause erratic contact?

That is why I asked if he used the OEM plug or hardwired. Those clips can be a concern.

Jim

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Posted by hustle_muscle on Friday, November 1, 2013 10:25 PM

Would soldering the decoder to the plug work for a better conductivity? I took the lights out and i'm still getting very mediocre performance.

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Posted by cacole on Sunday, November 3, 2013 7:21 AM

If you're absolutely sure your track and wheels are squeeky-clean and are not the source of the problem, you need to solder the connections on the truck pickups if they have plastic clips holding the wires in place.  Your description of "jerkiness" implies a mechanical problem or loss of electrical contact from the trucks due to dirty wheels or track, or loose wires between the trucks and circuit board, and not the decoder.  The wires from the trucks to the circuit board are a likely suspect.

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Posted by rrinker on Sunday, November 3, 2013 10:11 AM

 The other thing that can happen with those plastic clips is that a little too much wire can stick out and there could be just one strand touching another where it's not supposed to. They are unreliable at best, soldering is the best bet.

          --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by zstripe on Monday, November 4, 2013 12:34 AM

Hustle_Muscle,

First off, I would get rid of the, wire locks and solder the wires as suggested,then run it with the shell off and observe,the drive line,to see if the jerkiness, is mechanical,in nature. Good Luck !

Cheers, Drinks

Frank

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