The installation is for HO Scale Bachmann Spectrum 80 Ton Three Truck Shay. It uses TCS DP2X-UK decoder and was performed by A.G.
The three upper pictures represent the locomotive prior to the decoder installation. The TCS DP2X-UK will be fitted into the locomotive's tender.
Remove the Phillips screw that is circled in red.
There is a one Phillips screw that holds the tender's chassis and its shell together (circled in red) — remove the screw and gently lift the shell off of the tender's chassis.
The tender's shell and truck removed.
Here is a picture of the original light board with DCC ready plug (circled in red).
Remove the DCC plug that came originally installed with the tender. There is a capacitor across the motor circuit that drastically affects the speed curve when using a Quiet Drive decoder. It causes an over-speed problem. It must be removed from the circuit. Do this by simply cutting the capacitor leg out as shown in the picture above. The capacitor is typically yellow and has a marking of 105. The capacitors are placed in the circuit by Bachmann for the purpose of reducing the possibility that electrical noise generated by the motor when running would interfere with a TV or radio or cell phone or possibly some other electronic device. All TCS decoders have this capacitor built into the decoder and there for external capacitors are not needed. The TCS decoder is tuned to work with its own internal capacitor in operation. With external capacitors applied in the circuit, the result is a detuning which results in poor speed control. That is why the Bachmann applied capacitors need to be removed. The internal decoder capacitor reduces the possibility of electrical interference so there is no harm in removing the external capacitors.
Place our TCS DP2X-UK into the DCC socket exactly as shown above. Place the shell back, reinstall the Phillips screws and we are ready to go!
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