This installation is for a HO Scale Atlas C420 High nose using a TCS WOW121 Diesel Decoder, AS-MB2 NC Motherboard, KA4 Keep Alive® and 30mm WOWSpeaker with plug.
HO-Scale Atlas C420 High nose shown prior to installation. To start off this install, we must first remove the front and rear coupler screws and their housings. With the couplers removed, while gently pulling outwards at each end and lifting along each side of the frame, lift the shell off of the frame. Take care to release the handrails as you lift off the shell so they don't break.
The Atlas C420 High nose shown with the shell off. Remove the 4 screws and wire connectors from the original lighting board and remove it from the chassis.
Once the lighting board is removed, clip the four wire leads to the caps connected to the motor leads and remove them. Leaving these in place could interfere with smooth motor operation.
Next, remove the single screw found on the rear board and remove this from the chassis. Save this screw for reuse.
Finally, loosen the screw found on each speaker and swing the metal containment piece out of the way. Remove each speaker. These will not be reused.
The locomotive is now ready to do the install.
To address the rear board, unsolder the existing wire leads from the back side of this board.
Finally, solder new lighting wire leads to this board as shown to be able to connect it to the AS-MB2 NC. Using the original screw, mount this board back in to place. Utilizing this board in this way keeps the LED properly orientated to the light tube.
Next, clip the single small wire lead that is attached between the board and resistor. TCS motherboards include on board current limit resistors for LED use. There is no need to apply external resistors for LED use.
Set the WOWSound 30mm speaker into the frame opening and from the rear side, while keeping it flush with the frame edge, using hot melt glue, secure this into place. NOTE: You must be very careful to avoid getting glue on the speaker cone. Glue on the speaker will ultimately cause it to produce no sound and fail. Feed the rear track and lighting leads over the top of the speaker frame and secure them in place.
On the opposite side from your speaker placement, using a small amount of hot melt glue on the back of the speaker plug, secure this into the frame opening. It is important to use this plug as it greatly increases the volume and sound quality.
Next, using a small strip of foam, double sided tape on the front edge of the motherboard, set it in place into the small frame grove on the back of the front frame member. Using a small amount of hot melt glue, secure the motherboard in place with a bead of glue underneath the board against the frame edge, mounting it in place. Solder the track, motor, LED lights and speaker wire leads to the AS-MB2 according to the included wiring diagram.
Route the front LED wire leads along the bottom of the frame and using the same foam, double sided tape, mount the KA4 Keep Alive® to the frame as shown. Solder these wire leads to the motherboard according to the included wiring diagram.
You can now plug in your WOW121 decoder.
Lastly, in order to keep the wires neat and prevent possible shorts, lace the wires into a bundle using lacing cord, which is a wax impregnated string used for wire bundling and making harnesses. There are many choices of lacing cord available from Digikey www.digikey.com. We use part number 802534B BK032-ND
Close up the locomotive and reinstall the coupler assemblies. Be sure to be mindful of wire routing and reassembly of the shell as to not damage or foul the installation. Your Atlas C420 High nose is now WOWSound equipped and ready to roll!
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