This installation of TCS MC2 Decoder is for HO Scale Bachmann Spectrum Dash 8-40CW and was performed by Simon Griffin, IL.
The locomotive prior to installation.
Shell removal is accomplished by unscrewing the fuel tank and then removing the two screws that secure the body. The split frame is held together by 5 screws. Remove these and separate the frame.
The motor conductors are copper strips that can be clearly seen on the sides of the motor. These could be cut off. I elected to keep them in place and insulate them.
Solder motor wires to the copper contacts, top and bottom, and then insulate with tape. Kapton tape was used in this application. Make sure that there is no exposed copper contact that can then touch the frame when re-installed.
Replace the motor in the frame. To improve the reliability of the track pick up, wires were soldered to the conductor on the side of the truck. Make sure to clean the place where this solder joint is made as it is likely to be greasy.
Re-assemble the frame taking care to ensure that the insulator washers are in place. It is very important that the frame sides have no direct electrical contact. The gap between the frame sides provides space to feed the motor and track pick up wires to the top of the locomotive. Using a multi-meter check that there are no direct shorts between the motor wires and the frame/track pick up.
Remove the original light board from inside the shell. There is enough room for a small thin decoder. In this case I used an MC2 with harness soldering the wires to their appropriate colors. Insulate all solder joints. LED lights were installed with 1K ohm ¼ watt resistors inserted into the circuit.
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