Bachmann E7 -- II

My last post covered the Bachmann E7 out of the box. It wound up taking me several hours to get the shell off. Like many products from China, the screws seem to be driven in with a power screwdriver, and they can be torqued so hard that they're very difficult to remove. The E7 shell is held on with four screws, all of which took some work to loosen, but one of them was in so hard I eventually had to drill it out. Whew!

Here is the chassis with PC board:

The DCC socket is a standard NMRA 8-pin with a dummy plug. The difficulty here is that the DCC ready product has four different LEDs, but by default they are all lit, and they aren't separately controllable, as they would be on the prototype. One of the fun things about controlling lighting with DCC is, at minimum, that the warning light rotates or flashes and is usually not constant like the headlight -- but it's often not lit. (I've tried to find out on various forums, without success, what railroad rules cover when a warning light is turned on and oscillating and when it's off.)

However, a standard DCC decoder that uses an 8-pin plug and socket will not control the extra lighting functions. The one I'm most familiar with that will control Mars and other lights is the Digitrax DH166. This has a 9-pin socket with additional wires that will go to the additional bulbs or LEDs that represent Mars lights, numberboards, etc. The DH166 follows NMRA color code standards for these wires.

Unfortunately, the Bachmann E7's LEDs aren't wired according to NMRA color codes. Looks like I have more work to do to find out what wires from the Bachmann PC board control which of the LEDs on the chassis.