Non-sound DCC 0-4-2 Porter circuit board pinout?

Started by Flare, May 21, 2016, 06:55:49 PM

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Flare

So my Porter decided to stop working last night.

I suspect that the problem is the circuitry since I get the same problem in DC and DCC mode: Jerky/stuttery motion (if any) and the light isn't on unless it's moving.

Rather than send it in for repair, I would like to bypass what I imagine is the DC/DCC converter board and try re-wiring it for DCC-only operation with a standard decoder. (And possibly build a tender with a reversing light and additional power pickups while I'm at it.)

However, the wires leading into the loco aren't color-coded and I really don't want to take the thing apart to see where they connect.


Can somebody provide me with a diagram or schematic of the circuit board so I can re-wire it correctly?

Hunt

Click Here bottom right panel will help you identify the purpose of each wire.  Always best to confirm with multimeter.


Flare

Quote from: Hunt on May 21, 2016, 08:31:48 PM
Click Here bottom right panel will help you identify the purpose of each wire.  Always best to confirm with multimeter.



Thank you, but that only showed the side of the board I want to bypass.  Are the contacts on the other side the same?  (I don't have a meter)

Hunt

I do not have convenient access to a DCC equipped 0-4-2 Porter to verify the following info about tab label.

Other side of the PCB  - each tab is labeled with its function thus identifying the purpose of the wire connected to it.

Understand if you bypass (or remove) the PCB you will have to add a resistor in the light circuit.


To do the installation you want – get a multimeter and use it!  ;D



Hunt

This what the other side of the board in your 0-4-2 looks like? Note the label where the wires from decoder are soldered. 


Hunt


Is above what the other side of the board in your 0-4-2 looks like?

I expect it is same side as shown in panel. If other side not marked then follow traces on this side.


Flare

Well I took the board off the shell to follow the traces, and found that the rear side is fully marked on both ends.

I apologize for wasting your time with my laziness.   :'(


However, following the traces showed that the headlamp outputs get combined within the board.  To make a reversing light I'll need to wire up a separate resistor, and the ones on the board aren't marked the way the ones I used to get at Radio Shack were.  Any idea what strength I'll need to get?  (I plan to use an On30 Climax bunker for the tender if that makes a difference)

Hunt

Flare,
I do not know the specs of the LEDs Bachmann uses. I always use LED with known specs and calculate the required resistor. 

Good luck with your project.

Hunt

If you want to use or reuse a Bachmann installed LED, lookup or calculate its Ohms from the code on the SMT/SMD resistor used in the  light circuit on the PCB.


Hunt

Correction

Quote from: Hunt on May 22, 2016, 11:46:12 PM

If you want to use or reuse a Bachmann installed LED, lookup or calculate its Ohms the resistor's value from the code on the SMT/SMD resistor used in the  light circuit on the PCB.



What resistor value did Bachmann use with its installed LEDs?

Lookup (or use in online calculator) the code on the SMT/SMD resistor in the light circuit on the Bachmann PCB to learn its value (Ohms).



Hunt

Or ...
If you use a SoundTraxx Econami ECO-100 Steam (P.N. 881001) with the Bachmann LED, then wired in-series to a resistor, 680 ohms, 1/4 watts.   If that resister  takes up too much space try a 1000 ohm, 1/8 watts.