Replacing DC circuit board with DCC board

[TEXASAPPLE]

On the newer F7A diesel, is it possible to replace the DC board with a DCC board and, if so, are there any other modifications that need to be done to operate on DCC?

[Len]

This shows doing it to a Bachmann F7B, but the steps should be the same for the F7A. The steps would be the same for anyones hard wire decoder. Installation steps:

http://www.tcsdcc.com/Customer_Content/Installation_Pictures/N_Scale/Bachmann/F7B/index.html

Len

[TEXASAPPLE]

Thanks for the video link.  I've seen it before; it appears to deal with the Plus and Spectrum versions, not the one with a circuit board on the top of the frame.  What I really want to know is whether or not the motor is isolated so that replacing the existing DC board with a DCC board will work or if further work (like in the video) is needed.

[James in FL]

It appears the "newer" Bachmann F7's come equipped with a dual mode DCC decoder.
It's already on that board.

So... the answers to your questions are, yes the motor is already isolated, and no you wouldn't have to do anything else.
If you're talking about removing that board and hardwiring another decoder in there, you will have to figure out what to do with the lights.

Have a look here;
http://www.spookshow.net/loco/bachf7.html

Good luck

[TEXASAPPLE]

My F7 looks like the newest type, but the board on it is slightly shorter and is listed as DC, but if the motor is isolated, swapping out that board for the newer DCC one should work.  I'll let everyone know after I try it.

[skipgear]

Did the loco come in a train set? Those are the only DC F7's of the current design that I know of.

[TEXASAPPLE]

It came with a train set, but I have popped off the shell and know that it has a circuit board on top and appears to be the "3rd" type of F7 diesel.

[TEXASAPPLE]

Disaster!!  While working on the F7, I managed to knock out several small screw backings and disconnect a wire from the board to the motor.  I now have it in pieces to try and reconstruct later.  My advice is to be very careful or just leave well enough alone.  N scale engines are extremely small.

[TEXASAPPLE]

Got back into my mess.  Managed to solder the loose wire to the motor and more or less get everything into proper place.  Somehow, in the previous disaster the couplers and some spacer washers got lost, but with the shell back on, it's running again on DC.  Later, I will try to swap out the circuit board. 

[TEXASAPPLE]

I finally swapped out the circuit boards and it works! I now have two DCC locos. Now I need to install some couplers since the old ones never reappeared after my initial disaster.

On another front (which I have seen discussed elsewhere), the Bachmann decoder doesn't seem to easily allow you to set it to a new address. According to Digitrax, a resistor needs to be placed across the programming track to get the decoder to recognize commands. Do they mean to connect one end of the resistor to one rail and the other end to the other rail? That's how I interpret "across." Please let me know if this is right. (A diagram would help!!)

[Hunt]

A 1000 Ohm, ¼ Watt resistor across the programming track is required for CV read and programming  a non-sound Bachmann(Lenz based) decoder used with a Digitrax Zephyr(DCS50) or Zephyr Xtra(DCS51). Remove resistor after programming.

You have placement orientation correct. You only need to lay the resistor on the rails no need to attach. 

[Bucksco]

"the Bachmann decoder doesn't seem to easily allow you to set it to a new address"

The decoder is a standard NMRA decoder. The problem is most likely on the other end.....

[TEXASAPPLE]

The 1000 ohm resistor solution worked and I was able to change the decoder address.  Thanks for the tip, now all I need to complete the job are working couplers.