Roundhouse EMD Model 40 Critter

Scale:
HO Scale


This installation uses the following decoder:


TCS recommends using the DP2X-UK decoder for simple plug-and-play installation.

This installation documentation is for the HO Scale Roundhouse EMD Model 40 Critter. The original installation uses the MC2 decoder, and was performed by a TCS customer.

Important note! The directional lighting diodes mounted on the locomotive DCC plug board are mounted backwards!  Do not plug a decoder into the socket and turn on the lights. You will instantly fry the decoder! In later versions of this locomotive, Roundhouse corrected this issue. Unfortunately, there is no way for us to know when exactly this problem was corrected, but you can test this by reading the polarity of the diodes to be sure the light functions are not tied directly to the track.

The picture above shows the locomotive prior to the decoder installation.
The picture above shows the locomotive prior to the decoder installation.
With the shell removed, install the decoder into the 8-pin socket. If you are using the DP2X-UK, Plug in the decoder so that Pin #1 of the decoder lines up with Pin #1 of the socket. Pin #1 will be designated with a "1" or a small arrow/chevron. If you are using the MC2, follow the steps below.
With the shell removed, install the decoder into the 8-pin socket. If you are using the DP2X-UK, Plug in the decoder so that Pin #1 of the decoder lines up with Pin #1 of the socket. Pin #1 will be designated with a "1" or a small arrow/chevron. If you are using the MC2, follow the steps below.
After removing the "dummy" plug, plug in the decoder so that the Orange wire lines up with Pin #1 of the socket. Pin #1 will be designated with a "1" or a small arrow/chevron.
After removing the "dummy" plug, plug in the decoder so that the Orange wire lines up with Pin #1 of the socket. Pin #1 will be designated with a "1" or a small arrow/chevron.
After the decoder is installed, replace the shell.
After the decoder is installed, replace the shell.

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