Athearn SD70MAC Decoder Installation featuring the GEN-MB1 Motherboard with Keep Alive®, WOW121-Diesel Decoder, and UNIV-SH1-O Speaker Kit by TCS.
First, remove the coupler box screws and the coupler boxes from both ends of the locomotive.
With the couplers removed the shell should lift right off the chassis.
Remove the original lighting board from the chassis and remove the wires from the board tabs.
Clip the motherboard onto the motor just like the original lighting board.
Next, wire the GEN-MB1 according to the wiring diagram in the motherboard manual. This mother board has a 1.5volt power supply to power all the original 1.5v bulbs that come with the Athearn locomotive. It can be configured for LED operation as well, the mother board has built in current limit resistors for LED use. Consult the wiring diagram for LED use.
All the original 1.5volt bulbs supplied with the Athearn loco were used. The "FL" solder pad is the forward 1.5v solder pad for the front lights. The "RL" solder pad is the reverse 1.5v solder pad for the reverse lights. The ditch light bulbs are connected to the solder pads marked "1", "2". The solder pad marked "1.5V" is the common power source for the bulbs.
Next, glue the 35mm x 16mm WOWSpeaker into the UNIV-SH1-O speaker housing. Mount the housing face down on the frame over the rear truck, and solder the wires to the motherboard.
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.
Finally, plug in the WOW121-Diesel decoder and replace the shell and coupler boxes.
Your WOWSound equipped engine is now ready to run!
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