This installation of TCS DP2X digital decoder is for HO-Scale Atlas AEM7 and was performed by TCS.
The Atlas AEM-7 shown prior to installation.
As the TCS DP2X digital decoder is a drop in decoder for the Atlas AEM7 H0 loco, it can be installed simply by removing the top box cover, un plugging the existing plug and plugging in the new decoder. We do not recommend this however as the number board lights are directly connected to track power and it will not be possible to control these lights or even do programming of the decoder. To install the DP2X correctly, these light will need to be rerouted. To begin, remove the coupler screws highlighted above in red and the couplers. Then, remove the four screws highlighted above in blue and remove those assemblies.
Shown with the shell off.
To rewire the lights, remove the connectors FNBL1 & 2 for front lights and RNBL1 & 2 for rear lights respectively as highlighted above in red
from the circuit board.
Take a corresponding lead from each and splice them together. We chose to connect like colored wires, but it does not matter.
Insulate these with shrink tube such as TCS part #1320 Black 3/64" heat shrink tubing.
Solder the wire leads from the front and rear lights to the diodes as shown in the photograph above.
Next, remove the original plug as highlighted above in red and then remove the C-1 cap highlighted in blue above and discard it.
As the DP2X decoder has built in capacitors, this additional piece will interfere with the smooth running of the locomotive.
Plug the TCS DP2X digital decoder in it's place. You can now reassemble the shell to the chassis and reinstall the couplers.
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