This installation is for N Scale Atlas GP9TT (1997 edition) and uses TCS ASD4 Decoder and was performed by A.G.
These three pictures above show detailed Atlas GP9TT locomotive prior to the TCS ASD4 decoder installation.
Remove body shell and handrails by gently pulling up on the shell.
Here is the picture of the Locomotive's chassis with its shell taken off and original light board installed.
Remove the fuel tank.
Add some solder to the power pick-up tabs so that the Decoder will have proper contact with the chassis.
Loose the two Phillips screws that hold the two halves of the frame together and remove Locomotive's both trucks by gentle pull and twist to the side. Pull two copper power lines from both side of the chassis.
Take both halves of the frame apart, remove original light board that the locomotive came with and insert the ASD4 decoder. Make sure the motor tabs are not touching the frame- isolate them with kapton or electrical tape and make sure they ARE touching their proper spots on the underside of the
decoder as shown in the picture above.
Put both sides of the frame together and make sure that all four contacts of the decoder are fitted into the chassis so that they create physical/electrical contact. Install both trucks, power pick-up rails, and tighten the two phillips screws on the chassis. Place the shell back and test your locomotive on the track.
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