This installation is for N Scale Atlas SD35 and uses TCS AMD4 Decoder and was performed by Stephen VanMetre, MD.
Atlas SD-35 using a TCS AMD4 drop in decoder. I rate this as an easy install. Before starting this install, clean the locomotive wheels and your track so these items do not cause false indications later.
The fuel tank should pull off gently. Then using tooth picks on each side between the frame and the shell, the shell should pull off easily as one unit.
You will see that the two frame halves are marked L for left and R for right, this will aid in reassembly later. Remove the two screws holding the frame halves together, using a tooth pick, gently release the motor mount clips through the frame and separate the frame halves. Carefully remove all the components take note how they are arranged.
Using a pair of pliers, carefully squeeze the Board Contact Points so the decoder has a snug fit. With out doing this will result in no contact to the Decoder and it will not work. Now replace all the components into the R (right) frame half including the decoder making sure the decoder is facing right side up as shown in the wiring diagram in the TCS decoder manual which came with the decoder. Make sure the motor contacts are under the decoder during assembly. This could result in a short and damage the decoder if they are not under the decoder. Also make sure the frame spacers are in place, these also insulate the screws from shorting out to the frame. Replace the screws and gently snug them.
Set the locomotive on the programming track and check for an address, the address should come up as 03. If you find that your system will not read the address at this point, the decoder is not making contact with the frame. If your system indicates address 03, take the locomotive off of the programming track. Before setting the locomotive on the main track, dial up address 03 and make sure the throttle setting is at 0. Now, set the locomotive on the main track but do not turn up the throttle. Making sure the throttle is at 0 will prevent damage to the decoder if there is a short. IF YOUR SYSTEM INDICATES A SHORT, REMOVE THE LOCOMOTIVE FROM THE TRACK AND REPAIR THE SHORT BEFORE GOING ANY FURTHER. If your system does not indicate a short and the head light comes on, you should be ready to turn the throttle up and the locomotive should move. Enjoy.
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