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Atlas Classic GP9 Troubles!

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  • Member since
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  • From: Reading, PA
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Posted by rrinker on Sunday, November 24, 2019 12:14 PM

 Couple of other things for the next loco, if you get different ones. A common issue is the decoder PCB being thinner than the factory light board, so where the bare spots are supposed to touch the frame halves, it fits loosely, and either you don;t even get lights, or it runs very erratically. The usual solution to that is to put small blobs of solder on the contact points to make a tight fit in the frame.

 And many N scale loso, the motor tabs come up around the outside and wrap over the edge of the frame and to the decoder. On such locos it is almost alyways required to put a piece of Kapton tape on the side ti insulate the truck tabs/frame from the motor tabs. And Kapton tape is about the only thing that will work - besides being messy, electrical tape is too thick and you might have problems getting the shell back on. The motor tabs shorting to the frame or truck tabs WILL damage the decoder, so don't overlook this. Some decoders used to come with a piece of Kapton tape and the instructions sort of told you what to do with it.

 Those are the two most common issues with N scale installations, at least the relatively newer models where you can install the decoder without soldering wires. This is the first one I've seen where the motor tabs come up in the middle, where there is pretty much no chance to see if they are actually touching the decoder contacts.

                           --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 richhotrain on Sunday, November 24, 2019 11:30 AM

Trainzman2435
 

****UPDATE**** It's running....After taking it apart for about the 6th time i bent one of the motor leads just a little twoards the front of the loco so that it looked more in line with the pad on the decoder. Put it back together and tested it...Runs fine now.....Must have been not making contact with the pad on the decoder all the time

That is excellent news. Kudos to you for persisting. 

Rich

Alton Junction

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Posted by Trainzman2435 on Sunday, November 24, 2019 10:19 AM

richhotrain

 

 
Trainzman2435

Rich, i agree with you sir, very bad design....I'm half tempted to just go back to HO scale before i spend another dime on anything N scale related......:( 

 

 

The remark that I am about to make may cause some dissent among fellow forum members, but if you are not too far along in N scale, a return to HO scale could make good sense.

 

But before you do that, you are far enough along into this issue to see it through to resolution. If I were in your position, I would want to know what is causing this problem with your N scale locomotive.

Rich

 

 

****UPDATE**** It's running....After taking it apart for about the 6th time i bent one of the motor leads just a little twoards the front of the loco so that it looked more in line with the pad on the decoder. Put it back together and tested it...Runs fine now.....Must have been not making contact with the pad on the decoder all the time....Thanks for all the help and suggestions guys, i really appreciate it....:)

  • Member since
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  • From: Milton WV
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Posted by Trainzman2435 on Sunday, November 24, 2019 9:24 AM

richhotrain

 

 
Trainzman2435

Rich, i agree with you sir, very bad design....I'm half tempted to just go back to HO scale before i spend another dime on anything N scale related......:( 

 

 

The remark that I am about to make may cause some dissent among fellow forum members, but if you are not too far along in N scale, a return to HO scale could make good sense.

 

But before you do that, you are far enough along into this issue to see it through to resolution. If I were in your position, I would want to know what is causing this problem with your N scale locomotive.

Rich

 

 

Rich, i am going to figure out what is causing the problem lol...It is driving me nuts and i am a person that likes to know why something will not work as it should. Just curious....Is it possible that maybe i have the motor inbackwards which might in turn cause the motor terminals to be in the incorrect location when making contact with the DCC decoder pads or is it even possible to put the motor in the incorrect orientation or backwards?

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  • From: Dearborn Station
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Posted by richhotrain on Sunday, November 24, 2019 8:44 AM

Trainzman2435

Rich, i agree with you sir, very bad design....I'm half tempted to just go back to HO scale before i spend another dime on anything N scale related......:( 

The remark that I am about to make may cause some dissent among fellow forum members, but if you are not too far along in N scale, a return to HO scale could make good sense.

But before you do that, you are far enough along into this issue to see it through to resolution. If I were in your position, I would want to know what is causing this problem with your N scale locomotive.

Rich

Alton Junction

  • Member since
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  • From: Milton WV
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Posted by Trainzman2435 on Sunday, November 24, 2019 7:11 AM

richhotrain

 

 
rrinker

It does sound like it might be tricky to get the motor tabs to actually touch the decoder, so I susped there may still be an issue there.  

 

 

I operate in HO scale with the NCE PH-Pro, so I cannot be of much help here. When I first read the opening post to this thread, I wondered what it meant to have the motor tabs contact the decoder tabs. Then, I looked at photos of the decoder and I read through the manual. What an awful design.

 

I agree with Randy that this could be the source of the problem. Either that or you don't have the Power Cab set up right. Good luck!

Rich

 

 

Rich, i agree with you sir, very bad design....I'm half tempted to just go back to HO scale before i spend another dime on anything N scale related......:(

  • Member since
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  • From: Milton WV
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Posted by Trainzman2435 on Sunday, November 24, 2019 7:08 AM
Can anyone recommend a better method to make sure that i am getting good connection at the motor tabs, maybe solder a wire lead to each tab and to the decoder or??? It is impossible to look and see if the tabs are actually touching like they should be so i can only assume as i put the frame halves back together that the tabs are still touching....There has to be a better way to do this!
  • Member since
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Posted by Trainzman2435 on Sunday, November 24, 2019 7:03 AM

tstage

Is your Power Cab plugged into the LEFT connector port of your PCP panel?  If it's plugged into the RIGHT port the Power Cab will light up but your locomotive will not operate.  Since you state that the headlights operate then I'm guess that's not the issue.

Tom

 

 

Tom, thank you sir and yes....It is plugged into the left port!

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Posted by richhotrain on Sunday, November 24, 2019 4:37 AM

rrinker

It does sound like it might be tricky to get the motor tabs to actually touch the decoder, so I susped there may still be an issue there.  

I operate in HO scale with the NCE PH-Pro, so I cannot be of much help here. When I first read the opening post to this thread, I wondered what it meant to have the motor tabs contact the decoder tabs. Then, I looked at photos of the decoder and I read through the manual. What an awful design.

I agree with Randy that this could be the source of the problem. Either that or you don't have the Power Cab set up right. Good luck!

Rich

Alton Junction

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Posted by rrinker on Sunday, November 24, 2019 12:09 AM

 Looking at the directions, it shows applying some kapton tape along the narrow part of the circuit board to keep it from touching the frame, otherwise it should stay suspended in the slots between the frame halves. That seems to be OK, or the lights wouldn;t work. It does sound like it might be tricky to get the motor tabs to actually touch the decoder, so I susped there may still be an issue there. These motor tabs come up from the middle of the frame, other N scale locos, the motor tabs wrap over the top and can contact the sides of the frame. Doesn't look like that happens with this one.

 The insulaters they are talking about are the ones on the screws that hold the frame halves together. If you were missing those, the loco would likely short as soon as it was put on the track. When you took apart the frame halves to take out the factory board and installk the decoder, there should have been small plastic bushings in the holes where the screws went through.

                                          --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 tstage on Saturday, November 23, 2019 10:06 PM

Is your Power Cab plugged into the LEFT connector port of your PCP panel?  If it's plugged into the RIGHT port the Power Cab will light up but your locomotive will not operate.  Since you state that the headlights operate then I'm guess that's not the issue.

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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  • From: Milton WV
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Posted by Trainzman2435 on Saturday, November 23, 2019 10:01 PM
Just for the heck of it i decided to install another brand new decoder. I made sure both of the motor pads were contacting the pads on the decoder. Exact same thing happens...Lights work both frontward and reverse but will not even try to move. Wonder if it could be my DCC system? Its brand new but.....Also, does it make any difference which set of bogies go where, front or rear? Can they be mixed up? Does anyone have a picture of how the motor lead tabs should be oriented so they make optimal contact? I am at a loss.....2 brand new decoders and the same thing. The loco is new also and ran fine on DC......
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Posted by ba&prr on Saturday, November 23, 2019 9:36 PM

To me it sounds like the motor tabs aren't touching the decoder pads. With the body off, put the loco on the track, bring up low speed step, 2-5, push down on the decoder part where the motor tabs are. If the loco wants to move, there's the problem. You can solder a blob on teh decoer tabs or try to wire the motor tabs to the decoder.   Joe 

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Posted by tstage on Saturday, November 23, 2019 7:47 PM

Trainzman2435
an anyone maybe show me what you mean by the decoder board making contact with the frame...

Trainzman,

Basically any soldering pad or surface-mount component or bare wire connected to the decoder that could make contact with any metal surface on the chassis and cause a short.  Cover the bottom side of the NCE decoder with electrical tape as a short-term solution.  If you are planning more decoder installs in the future, it's worth investing in a small roll of Kapton tape (e.g. 3/8" wide), which is very thin, tough, holds well, and won't leave a gooy residue like electrical tape when it gets warm.

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

  • Member since
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  • From: Milton WV
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Posted by Trainzman2435 on Saturday, November 23, 2019 7:14 PM

rrinker

If the decoder board is making contact with the frame, the lights will work. Sounds like the motor tabs aren't making contact, even though you said you checked it. OR, the motor tabs are touching the frame. This can fry the decoder, or just make it not work. Tom's advice is a good idea - remove the decoder and rewire it for DC and see if it works on plain DC power. If it doesn't work that way, it won't work with a decoder.

                              --Randy

 

 

 

Okay, i will check the tabs as well as add some tape to prevent any contact from the motor tabs to the frame....Also, i was running the loco on just regular 12v DC before and it ran fine. Can anyone maybe show me what you mean by the decoder board making contact with the frame, maybe a picture or something? I ma not sure where the frame isolators are that the NCE DCC decoder package directions mentions.....Thanks again guys!

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Posted by rrinker on Saturday, November 23, 2019 6:26 PM

If the decoder board is making contact with the frame, the lights will work. Sounds like the motor tabs aren't making contact, even though you said you checked it. OR, the motor tabs are touching the frame. This can fry the decoder, or just make it not work. Tom's advice is a good idea - remove the decoder and rewire it for DC and see if it works on plain DC power. If it doesn't work that way, it won't work with a decoder.

                              --Randy

 


Modeling the Reading Railroad in the 1950's

 

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

Moderator
  • Member since
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  • From: Northeast OH
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Posted by tstage on Saturday, November 23, 2019 5:50 PM

Trainzman,

If you have a DC power pack, remove the decoder and test your GP9 using a small piece of track.  If there's a shorting or electrical issue then it should show up there, as well.  If it runs fine on DC then it's either an issue with the [bad] decoder, or the decoder is making contact somewhere on the chassis.

Tom

https://tstage9.wixsite.com/nyc-modeling

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

  • Member since
    October 2019
  • From: Milton WV
  • 253 posts
Atlas Classic GP9 Troubles!
Posted by Trainzman2435 on Saturday, November 23, 2019 5:09 PM

Hello everyone, i am hoping that someone can shed some light on a problem i am having. I have a new Atlas Classic GP9 DCC ready loco in N scale. I purchased the NCE N12A2 decoder and installed it. I sat it on my track and turned on my NCE powercab DCC system. I selected loco 3 as it instructed just to try it out. The loco WILL NOT move or even attempt to move in either forward or reverse. The forward and reverse lights both work when selected but it just will not try to move. If i attempt to move it by hand it makes both the forward and reverse lights flicker. I have removed the decoder and reinstalled it several times to be sure that the motor contacts are touching the pads on the DCC decoder. Can anyone please shed some light on why the lights will function but the loco will not even attempt to move? Thanks!

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