This installation is for N Scale Atlas 8-40CW and uses TCS AMD4 Decoder and was performed by A.G.
This is a fairly easy installation that requires some programming skills.
The upper three pictures show the Atlas 8-40CW with its shell on.
Gently remove the locomotive's shell starting from the cabin side as shown in the picture above.
This picture shows the locomotive's chassis with its shell taken off and the original light board.
This locomotive uses separate LEDs for ditch lights so a four function decoder is needed. A close-up picture of the ditch light board is shown in the picture above.
Gently unsnap the fuel tank as shown in the picture above, remove the light shield, and desolder the four ditch light wires (circled in red).
Here is a close-up picture of the desoldered ditch light wires.
Using philips screw driver loosen the rear and front screws (circled in red) without removing them. Using the flat head screw driver spread the chassis far enough apart to remove the original light board.
Place some solder on the four decoder's power pick-up tabs as shown in the picture above. The reason for doing it is to make sure there is proper contact / fit between the decoder and the chassis (see the step below).
Place the TCS AMD4 decoder so that two motor tabs (that are underneath of the decoder) are lined-up with motor pads of the decoder, and make sure there is a tight fit in all four (circled in red) connections. Tighten the front and the rear philips screw so that the chassis stays together.
Because of the fact that the LED pads are placed on the opposite end of the decoder, some wire extensions are needed.
Using the manual that came with the AMD4 decoder, solder the wires to the proper pads on the decoder.
Here is a picture of the installation prior to the final wire arrangement.
Here is a picture of the Atlas 8-40CW's chassis with the TCS AMD4 decoder installed and the light shielding placed. Put the shell back on being very careful not to break anything.
Because of the fact that ditch lights are being used some function remapping is needed. Function #1 is the green wire and function #2 is the purple wire. Before function remapping, the right ditch light lights constantly when function button one is pressed, and the left ditch light lights constantly when function button two is pressed. What we want to achieve here is that both ditch lights should be blinking when the locomotive is moving forward and should be activated with a press of one button.
Green wire (function 1) CV35 = 4
Purple wire (function 2) CV36 = 4
At this point both ditch lights will turn on with a push of a single button (function button 1) and will begin blinking with a push of function button 2
To make the ditch lights blink in the forward direction we need do the following:
CV51 = 10
CV52 = 11
Now the locomotive should be ready to go!
Important Soldering Tip
Please do not use any flux either liquid or paste on the mother board. Over time, the acidic properties of liquid or paste flux will begin eating away at the fiberglass PCB and will damage it. Use only Rosin-core solder or no-clean flux approved for electronics use.
TCS recommends the use of Kester "44" Sn63 Pb37, .015" diameter Rosin-core solder. Kester part number 24-6337-0007.
You can order this solder from the following retailers:
Digikey - PN:KE1110-ND
Techni-Tool - PN:488SO6775
Other solder tips
When stripping wire, only strip a tiny little bit of the insulation. Strip no more then a 1/64 of an inch. When the wire gets tinned with solder, the insulation will shrink back more. Try to not expose any more wire then half the length of the solder pad at most. In no case should solder or exposed wire wire ever be outside the boundary of the the solder pad you are attaching a wire to.
Click here for important information on properly Stripping and Tinning wire