This installation of TCS A4X Decoder is for HO Scale Stewart Baldwin DRS 4-4-1000 RS-12 and was performed by TCS.
First lift the shell off of the locomotive and you will be presented with the lighting board as shown below.
Next remove the two screws in the top of the lighting board, disconnect the motor tabs, and the track pick-up wires from the the original lighting board and remove it from the locomotive.
Mount the A4X decoder where the lighting board was and replace to the screws to hold the decoder in place.
Attach the track pickup wires to the decoder as shown above. Next, trim both motor tabs down by about 1/2 inch as you can see in the image above. Attach two wires (one to each motor tab) and connect those wires to the motor tabs on the decoder as shown above.
Install a forward facing LED as shown above. Use your decoder literature to identify the correct pads to use for LED's.
Finally, install a rear facing LED as shown above and replace the shell. You are now ready to run!
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