Athearn RTR SD40 pick up issue

[CPRail]

Hi Group,

I've got an Athearn RTR SD40 that I've put a LM-2S and a iPhone speaker into, using the Athearn board. It ran with no hassles at home all over my layout. Took it to a friends layout who is using NCE DCC and it worked fine until the electrical bugs started bothering the whole layout. Then it would barely move one wheel revolution before cutting out.

It ran fine on the host's test stand, but put it on the layout and no joy. There were no error messages on RailPro, but it kept losing connectivity when it died.

Figuring the gremlins were out in full force that night (boy were they ever - how we got the op session done, I have no idea), I switched to using the Host's power (at least they would move) and packed my units up.

At home, I cleaned the unit all up, hard wired the truck wires to the board, ensured the solder connections between the wires and trucks were fresh and solid. All good. Put it on the track, and it runs fine until it gets to a switch, and then it has a momentary loss of contact, fires back up and continues on.

Again, no Error messages.

I did have to pull the weights from the Athearn chassis to get everything to fit. Could that loss of weight be enough to cause the problems? Do I need to ditch the board and hard wire everything?

It seems that you can get a loss of contact just by lightly touching one side of the unit (maybe a .5% tilt either way), but I can't confirm.

Model Railroading is Fun!! 

Ian Lisakowski

[Alan]

Sounds like you may have only a single wheel per side picking up power.

[nodcc4me]

If it originally ran well on your layout, I don't think the weight removal is the problem. You said you cleaned it up, but did you give the wheels a good cleaning? If your friend's track was dirty that would cause problems for the module.

[CPRail]

Yes, wheels were the first thing I cleaned, as I knew that there were some seriously dirty sections we were running on. I even cleaned the track on my layout just in case.

Took the meter to the wheelsets and trucks and it showed power coming on both sides.

Ian Lisakowski

[Alan]

The rocking observation you made caused me to think wheel problems. Do the trucks move freely in both x and y axis? Do all of the wheels touch when observed on a plate of glass?

[KPack]

I have heard reports from others that the wires Athearn uses to carry power from wheel to board can sometimes break internally.  They are stranded wire, so theoretically they should resist breakage more than solid wire.  However I've noted that the individual strands in the Athearn wires are very weak.  It's possible that one or more may be broken, but that's not easy to diagnose without replacing all the pickup wires.

The other thing it could be is an issue with power transfer from the wheels to the wire itself.  Sometimes a material like Conducta-lube or Neverstall can improve the electrical conductivity, but I've found that to be a temporary fix.  It usually wears away and can also gather dust.

Lots of different things it could be here.  I'd methodically go through the suggestions found on this thread and rule things out.

-Kevin

[KPack]

One more thing....is this one of the Athearn RTR where one half of the power is transferred through the frame?  Those are the worst.  If that's the case you'll be better off soldering wires directly to the trucks eliminate all the potential power loss connections from the trucks to the frame.

-Kevin

[CPRail]

I don't think it has any power going through the frame. There are 2 wires from each truck which connect to the respective board ends. I've personally soldered the wires to the trucks and the board.

I'll have to try the glass test when I get home. Last time I checked the trucks appeared to move freely in the x and y axis, but I'll double check. I'll also see if the wires are broken internally with my meter - it's not too hard to put new wires in.

Thanks for the thoughts - keep them coming.

[Antoine L.]

I have had only problem with Athearn RTR GP40. I did all by the book, isolated motor from frame, hardwired everything from power pick ups. Bleh, Done it all 3 times. At some point I managed to have the unit running only to find out the clutter of wires were pressing against the flywheels. Athearn RTR are mostly new versions of the bluebox same old technology, in my humble opinion.

Take your time and it might work at some point. Mine will go back to DC operations on a shelf layout.

Antoine

[CPRail]

Happy New Year Group!

It took a ton of time and head scratching, but I finally figured out the problem.

Turns out the Athearn DCC Quick Plug board got pooched somehow. I’m not sure if it was the layout I was operating on that pooched it, or a fellow operator's DCC power issues or what, but I took a chance and swapped it out for another Athearn DCC Quick Plug board and problem solved!

My Old Man and I also figured out how to hard wire a 9 pin plug into an Athearn engine (he had a bad board on a unit as well), so it was a productive afternoon!!

Cheers,
Ian

[CPRail]

In case anyone is wondering the out come with this loco, installing a Keep Alive saved the day!