Atlas HO S2 Decoder Install Pics

[nbrodar]

I did the DCC conversion on my Atlas S2 today:

Normally, I use TCS decoders, but for my S2s, I use NCE ATLS4 decoders, because they come with everything you need for the conversion, including the white LEDs.

Unsolder the truck pick up wires and remove the factory circuit board.


Before you remove the motor to isolate it, make sure to mark the top, so you can reinstall it in the proper orientation.

I forgot to take a pic of the me isolating the motor (I did that last night, and didn't really want to disassemble the drive train again). The bottom metal motor mount screw gets replaced with a nylon one, and you can see the Kapton tape isolating the motor from the from through the hole in the frame.


While the NCE instructions say to solder the rear LED directly to the board, I prefer to use short wire leads. This makes it much easier to install the rear headlight in the cab, without pushing on the decoder board. If you push down on the board too much the decoder may not make proper contact with the motor, and the unit doesn't go anywhere.


After attaching the new leads, I clip the LED leads as close as possible to the wire. Don't forget with was the longer lead, it goes in the top hole on the board.




The decoder installed (the top metal motor mount screw gets reused) and everything solder back together


I do the programming, and a test run before replacing the shell, in case I messed something up. It's been known to happen.

Fitting the rear headlight into the cab. I use a piece of electrical tape to keep the light transmission down.




Close everything up and you're ready to go.

Nick

[dekon]

Nice write up and pictures. Just wondering, is there any benefit to trimming the LED leads and using wire as opposed to using the bending diagram that comes with the decoder for the rear LED?

OOPS, sorry I missed your explaination on why you used wire.

[nbrodar]

Richard, no problem.

It was a very frustrating trouble shoot with the first one. The unit ran fine without the cab, as soon as, I put the cab on the darn thing didn't move. Finally, I realized the cab roof pushing on the LED, bent the back board down, and lifted the middle of the board off the motor contact. After that, it took a couple of tries to get the LED leads bent properly.

I used short wires on the next install, with must better results. So, I used wires on every install since.

Nick