Hi, I need help to install a keep alive in a Scaletrains n-scale AC4400CW

[gi-depp]

Hello, I would like to install a keep alive in my AC4400CW, but I don't know how to connect it.



Thank you very much in advance

[John]

I don't recognize the decoder.   

[gi-depp]

The decoder is on the bottom of the board, it's a DN1137e24.
I had hoped I could connect it to the board.

[peteski]

E24 connectors has pins for decoder's ground and for the "blue" raw rectifier voltage (those are the connections for a keep-alive), but if (like Atlas) Scale Trains did not make those connections available on extra solder pads on their light board, things will get more complicated.

Maybe reading thru the suggestions in https://www.therailwire.net/forum/index.php?topic=58111.0  will give you some ideas on how to proceed, although the keep-alive hookup is specific for ESU decoder.  If I had one of those light boards (and the Digitrax E24-based decoder) on-hand I could provide more details on connecting the keep-alive.

[signalmaintainer]

The decoder is on the bottom of the board, it's a DN1137e24.
I had hoped I could connect it to the board.

If you were willing to swap the Digitrax decoder for a Zimo MN140E24 or MS540E24, each has dedicated pads for connecting a keep alive.

[peteski]

If you were willing to swap the Digitrax decoder for a Zimo MN140E24 or MS540E24, each has dedicated pads for connecting a keep alive.

Maybe Scale Trains did make the ground and U+ voltage pads available on their light board, but I doubt it.   Can't tell without seeing the both sides of the board.

However any ZIMO or ESU decoders will be superior to Digital, and I suspect the price is also comparable.

[kiwi_bnsf]

Unfortunately all the Scale Trains N AC4400CWs (and all the more recent Scale Trains Dash 9s) ship with a light board that omits termination of the GND pin on the E24 connector. I have sent feedback via email, but I doubt the board will change anytime soon (they stated that they outsourced the board design to ESU).

This omission of pins / pads is an increasing trend with Atlas and Scale Trains E24 light boards.

I wonder if ESU could be persuaded to make a derivative of the Loksound Nano that has GND, U+ and power pack control pads on it (for a cost of an additional millimetre of length).

The ESU Loksound NEXT18 Micros had nice solder pads that facilitated a direct Keep Alive connection.

[gi-depp]

U+ is on board but not a GND connection, for whatever reason.
So I ordered a Zimo.

Thank you very much for your help.