Forney Circuit Board Wiring

[nosamnod]

Hello all,

Wonder if anyone can help me?

I have acquired second-hand an originally 'sound fitted' Bachmann On30 Forney which has had all it's circuit boards and wiring stripped out and which has been converted back to non-sound 'DC'.

However, the two little green circuit boards have been supplied with it, with a mass of loose wires still attached to both (no 8-pin plug).

Does anyone (possibly Bach-man?) know if there is such a thing in existence as a wiring diagram for this engine, so that I can re-instate the original DCC circuit boards and sound? I have an 8-pin plug to hand and am quite competant with wiring, so all I need is to know what wires attach to where on the two circuit boards and which where on the boards to connect the various wires from the pick-ups and motor.

Thanks in hope.
Don Mason - Nottingham, UK.

[richg]

Trace it out with an ohm meter unless someone has done that. Bachmann does not supply wiring diagrams. With a knowledge of DCC wiring and electronic components, you can do it.

Tsunami suggested by SoundTraxx is listed below. The Tsunami 750.

http://www.soundtraxx.com/choose/step3.php?t=o&s=Bachmann

Everyone, store the link and read up.

Rich

[nosamnod]

Thanks for the suggestion - which I am sure was made with all good intent - but anyone can simply buy a Tsunami and put it in ...and it would cost me around £80.

The whole point of my question was that I already have a perfectly good ex-Forney Decoder/Sound board to hand which has cost absolutely nothing and which will drop perfectly into place and simply needs hooking up. So why would I want to spend (ie waste) another £80 of hard earned cash?

If it were not for the fact that I already have this, then I wouldn't be buying Soundtraxx anyway - I would be going for Zimo (preferably) or Loksound, both of which are in my opinion infinitely better than Soundtraxx.

And with due respect, in my opinion few serious modelers would want the rather toy-like 'Fireman Fred' sounds anyway, so that really is not a consideration.

[nosamnod]

Sorry - Didn't mean to be offensive. Bit stressed out right now due to 3 recent family bereavements in pretty quick succession.

On re-reading my post it was a bit OTT. Not intended to come over that way. Please accept my apologies.

- Don

[richg]

Ok, can you try to get a couple decent photos of the PC boards.
Are two PC boards still wired together or separate?
I do know, the left and right rails feed a full wave bridge rectifier on one PC board which consist of four diodes.
Each motor lead will be connected to an inductor. Capacitor or capacitors might be right next to the inductors.
On the PC boards,
R = a resistor
C = a capacitor
D = a diode
L = a inductor.

Rich

[terry2foot]

in the absence of a wiring diagram, then surely a decent picture of the original factory installation or better still access to one (borrow a loco?) would work?


Terry

[richg]

No idea if you are coming back but be aware that Bachmann does not use the standard NMRA color's for the wiring which does not help.
I have the HO 4-6-0 with on board sound and the sound decoder does plug into the Bachmann PC board.
The On30 Forney seems to have the same configuration according the diagram for the Forney loco.
The best that I can see, two wires from one PC board go to the loco headlight, two wires to the tender light. Two wires to the loco motor. Two wires for the track power.
The two wire connector from the loco is only for track power.
The four wire connector is for loco light and motor power.
The decoder board would have two wires to the speaker and an eight pin plug wired to the decoder board plugs into the other PC board.
We do need a couple photos of the two boards.

Rich

[nosamnod]

Hi Rich,


Thanks for all that. I've been a bit up to the neck in stuff over the last week or so and will be for the next couple of days - but I'll get a couple of photos during the week and come back on this.

Please bear with me.

Thanks again - Don

[nosamnod]

Rich - and others.

I'm sorry - I've not got around to the photos yet and am away all next week.

I will try and get back on this when I return. Thanks for your patience.

- Don

[richg]

No problem.

Rich

[Ballard Southern]

Hello,    I'm very glad I just stumbled onto this thread and am going to go back and study it harder.  My problem is the opposite.   I bought the Forney thinking to try the sound feature.   I run busy yard operations and after a session with the sound, I'm ready to shoot the blasted thing      I want to get in there and see about disconnecting it.

Sort of aside, but if I could I'd disconnect the entire DCC function, don't need, use or like it for my own operations, but all the Bachmann's come with it now.  Being a DC lover I'm feeling kind of like a salmon trying to swim upstream.

Dick in Seattle

[MRRSparky]

If your loco is like mine, all the wire positions are marked on the UNDERSIDE of the Soundtraxx board.  All the wires are marked for color code, including two for Blue so you can land the common blue wire for front and read headlights separately.

Now for the heresy part:  I eliminated the Bachmann board entirely.  It is only there to accommodate European wiring requirements, and to give the ability to simply plug in the sound board.

As to soldering to the sound board, place a tiny bit of flux on the bared wire to be soldered to its tab, and onto the tab, and using a small solder tip with a drop of solder on the end, just touch it to the end of the wire as it protrudes through the little hole.  Make sure you are using non-acid flux and solder.

Scott Groff

[MRRSparky]

I should add something about the Bachmann wiring.  Don't rely on their color coding.  Get a multimeter and set it for continuity checking.

Place the loco on a length of rail, and keep probing wire ends to determine which is right rail (red), which is left (black).  One probe goes on the right rail and the other on one of the wire ends until you get a beep.  Repeat for the left rail.

Next, get a 9-volt battery and note which terminal is positive.  Now that you have eliminated the two wires that are the track pickup, pick two more that might be motor power and keep probing with a set of test leads to find out first which are the motor leads, and which is the positive (orange) lead.  The positive orientation will result in the loco jumping forward.  You can change this is you get it wrong with CV29 but then the direction of headlight operation will be wrong.

Finally, get a1.5 volt battery and probe the remaining wires for headlights.  Bachmann uses LEDs which are polarity sensitive.  Again, find the positive side of the battery and with test leads, keep probing until you get the headlights lit.  DON'T use anything greater than 1.5 volts or you'll blow out the LEDs.  You can replace the LEDs but it isn't a lot of fun.  I replaced all of mine as I didn't like the very orange glow.  More like a camp fire than a headlight.

Scott Groff