This installation of TCS MB3 Motherboard, WOW121 Decoder, and 20mm WOWSpeaker is for the HO Scale Bachmann 2-8-2.
The MB3 includes onboard Keep Alive® to keep you running smoothly over any troublesome track.
First, remove the tender shell by spreading it slightly and lifting it up and off. Now you can separate the coupling between the engine and the tender.
Next, unplug the decoder and the engine from the original Bachmann motherboard. You will find two wires soldered directly to the board. Clip these off as close to the board as possible.
With the wires clipped off your tender should look like the image above. Now you can remove the two screws highlighted above in yellow and remove the original motherboard from the tender.
Place the TCS MB3 into the tender as shown above and screw it into place with only the front screw. The back screw prevents the decoder from being installed so we will leave that screw hole empty. Now you are ready to solder the Red (rear truck) and Black (front truck) wires you clipped off the original board to the Red and Black pads identified above (highlighted with yellow arrows).
With the motherboard installed and the track pickups soldered in place, you can now move on to installing the speaker.
Begin by removing the coal load from the tender shell.
As you can see above the coal load has 4 sets of tabs holding it in place so you will need to compress the sides of the load as you tip it out of the tender.
Place your speaker (in this case a 20mm Round WOWSpeaker) into the coal load and mark its location. Remove the speaker from the shell and using the outline you marked drill the sound venting holes in the coal. For the 20mm Round WOWSpeaker we drill ~50 holes with a #68 drill bit.
With the holes all drilled you can mount the speaker inside the coal load. For this mounting we used hot glue, first to create a little standoff around the speaker and then to seal and mount the speaker within the shell.
With the speaker glued in place, you can solder two leads to the outside pads of the speaker as shown above.
Remount the coal load inside the tender shell and solder the two leads that are attached to the speaker to the two speaker pads on the MB3 as seen below.
Now you can plug the engine into the tender, plug the decoder into the MB3, and replace the tender shell.
You are now ready to run your locomotive!
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 than a 1/32 of an inch. When the wire gets tinned with solder, the insulation will shrink back more. Try to not expose any more wire than 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