This installation documentation is for the Atlas Dash 8-40B. This installation uses the AMD4 decoder, and was performed by SK.
Locomotive prior to installation
Remove the locomotive shell by gripping the fuel tanks and shell, and rocking the shell back and forth. Remove trucks, fuel tank, and light shield from the chassis. Loosen the screws that hold the frame together and separate the two halves. Gently remove the light board and retain the small brass contact tabs - they can be recycled and placed on the new board.
Prepare motor tabs for the AMD4 by bending them upwards. They will make contact with the board by passing up through slots on the decoder.
Unfortunately, one of the tabs was damaged on this decoder, so we opted to drop solder onto the board in place of all four.
Detail image of the AMD4 with soldered pads for frame contact.
Test fit the decoder onto the chassis and adjust the level of solder on the tabs until the fit is snug. If recycling the brass tabs, fit them over the small indents on the new decoder and press the board into the frame.
Isolate the motor from the frame by applying a thin strip of Kapton tape onto the frame where the motor tabs are most likely to come into contact with it. I soldered the motor tabs to the board to guarantee consistent contact and reduce potential motion, but this step is not essential to this installation. Make sure to give the locomotive a test run to make sure everything works properly before replacing the shell and finishing the job.
Important Soldering Tip
Please do not use any flux either liquid or paste on the mother board. It will damage it. Use only Rosin core solder approved for electronics use.
We recommend to use only Kester "44" rosin core, SN63PB37, .015" diameter, part number 24-6337-0007.
This can be ordered from Techni-Tool under Techni-Tool part number 488SO157
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