This installation is for N Scale Bachmann EMD DD40AX uses TCS M4 Decoder and was performed by A.G.
The three pictures above show detailed chassis of the Bachmann EMD DD40AX prior to TCS M4 decoder installation.
Remove the fuel tank by pulling it off the chassis.
Gently, pull the shell stright up. The picture above shows the original light board after the shell removal.
Using small philips screw driver, remove the front screw.
Do the same for the rear screw.
Desolder the orange wire (together with the yellow capacitor that is attached to it) from the original light board.
The original engine comes with Bachmann digital decoder so we need to remove it by desoldering all its wires from the original light board. Solder wick is used to clean all holes (as shown in the picture above)
The picture above shows removed Bachmann digital decoder.
The TCS M4 decoder was used for this installation. All holes on the original Bachmann board are numbered from 1 to 8 so you need to solder the right wire to the right color according to this scheme:
Orange wire goes to solder point #1
Yellow wire goes to solder point #2
Green wire goes to solder point #3
Black wire goes to solder point #4
Red wire goes to the solder point #8
Blue wire goes to the solder point #7
White wire goes to the solder point #6
Gray wire goes to the solder point #5
Here is the original light board with soldered TCS M4 decoder. The decoder is hidden under the board.
The picture above shows finished TCS M4 decoder installation.
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