The MC2 decoder was wired into the circuit board supplied with the loco. The MC2 is a good choice for this installation because of its small size and convenient harness. Remove the shell by removing two screws located on the underside of the frame. The two yellow capacitors marked C1 and C2 must be removed. See photos below.
Shown with shell on, prior to installation.
This photo shows light board before decoder is installed. The two yellow capacitors marked C1 and C2 must be removed. Remove them by cutting the leads off flush with the board or unsolder them. It is important to cut them as flush as possible to the board to allow room for the MC2 decoder. Also the copper jumper tabs must be removed.
This photo shows MC2 decoder installed. Notice the two yellow capacitors are gone and the MC2 decoder is in their place. The decoder is held in place with 1/4" wide Kapton tape. The leads were kept just long enough to allow for a very tidy installation. The solder pads on the light board were tinned. The wires were tinned Then the wires were soldered to the light board. It is not necessary to pass the wires into the holes in the light board. In this installation, they were just soldered flat on the pads. The pads are numbered starting with 8 on the left then 1,2,4,5,6,7 (three is skipped). Solder the wires as follows: 8= red, 1= orange, 2= yellow, 3 is not there, 4= black, 5= gray, 6= white, 7= blue.
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