Retracing Steps - Stationsounds Assembly

What's the part number of the motherboard you're using?

John,

The part number is 6912MB00AB. This motherboard assembly came out of the 15545 Santa Fe Dining Car from 2005.

I was hoping I had a reference, but I don't find one.  However, if you trace out the connector wiring, the two pins that go to pin 19 and pin 21 of the audio board are the two that you want to connect to the reed switch.  Make SURE nothing in that circuit connects to the frame.

Thanks John,

The frames (both floorboard and underbody frames) on this particular passenger car are made of plastic, but I will be raising them anyways with foam tape.

I would assume they would connect there or the pins marked CGND and CIN under the J9 plug (where the old hall sensor plugged into).

For the hot and ground leads, I assume they connect to the ones in the top right corner marked 3RD/GND rather than the ones in the bottom left with the capacitor soldered in.

Mikado 4501 posted:

The last parts I need to finish is wiring the hot and ground leads from the trucks and mount the ‘clickety clack’ sensor. However, my mind is a little fuzzy figuring out where on the circuit board they go to.

The old sensor it came with is being replaced with an ERR type chuff sensor used in their steam sound kits because they’re easier to mount. These have two wire leads whereas the old Hall effect sensor had three (where the J9 plug outlet is).

 

Thomas,

Your reed switch goes to the two pins of the J9 socket marked CGND and CIN. It does NOT use the pin marked +5, which would be for the hall-effect sensor.

Also, I'd double-check your wiring of the 9-pin plug/socket. The volume pot is PHI/PWIPE/PLO, and knowing that Lionel usually used a green/yellow/blue wire color scheme for that, it doesn't line-up with what you've shown. But I'm just guessing, as I don't know what's on the other end of the wires shown in your photo.

TRW

gunrunnerjohn posted:

Make SURE nothing in that circuit connects to the frame.

I'm not sure that's true in these earlier RS4-era boards. Ground is ground.

It's the later boards where one needs to keep the chassis ground separate.

TRW

Todd,

You’d be right on the volume pot wires. For this one, though, they gave the white, brown and blue wires to the volume pot, and the green and yellow ones to the run/program switch.

PaperTRW posted:

gunrunnerjohn posted:

Make SURE nothing in that circuit connects to the frame.

I'm not sure that's true in these earlier RS4-era boards. Ground is ground.

It's the later boards where one needs to keep the chassis ground separate.

TRW

I believe you're right, but I've never gone wrong recommending people be VERY cautious about mixing AC and DC ground.  There is no reason to connect the reed switch to frame ground, so this is 100% certain not to be a problem.  Also, if later he happens to have the RS-Lite board (or a new ERR RS Commander), he won't get careless and ground one of those pins.

I finished installing the reed switch and magnet for the car. All that's left is the hot and ground leads. I opened up my Blue Comet car I upgraded thanks to @PaperTRW and found the hot and ground leads were in the J2 socket on the circuit board.

However, that board is the older vertical stacked boards - much like in a TMCC locomotive - whereas the one in question (part number already listed above) has them stacked horizontally. I figure both would receive the hot and ground from the J2 socket, but I just want to be sure.

BTW, I've been on and off due to college resuming this month.

I guess that depends on what the J2 socket is.   Different motherboards will have different connector designations for their connectors.

In the upper right corner underneath the board, both the J1 and J2 sockets lead to both 3RD and GND points. My multimeter says they both connect in either one.

Thomas,

I'm unfamiliar with that exact motherboard as well, but you're likely on the right path. If you check the three 2-position Molex connectors with a meter, I'm reasonably certain that you'll find them tied together. Generally speaking, two of the three are where the hot/ground from each truck get plugged into, and the third is a connection to power a motor driver board -- which wouldn't be found in your StationSounds car.

So long story short based on your photos, J2 is one of the places you can connect power to the board.

TRW

Yep, those two are the power and frame ground, you have that right.

Alright, I've wired and tested the car now (back from school).

Everything seems to work fine except for one aspect - the reed switch to trigger the clickety-clack sounds. They don't trigger when the car moves along the track. I can hear the speaker get some minute response from the sensor whenever I spin the wheel with the magnet on, but not the familiar clickety-clacking. The wiring should is correct - each of the reed leads go to CGND and CIN individually - and is wired the same way as the Blue Comet car.

Just as a test, try a different RS4 board.  Maybe something is dead in the RS4 board.  If so, you can move the SS Diner chips to a different board.

Alright, it’s been a few months, but I finished my excruciatingly tiresome semester and can get to fully finishing this project.

I tested the Santa Fe RS4 board in another assembly, and tested another RS4 board in this one.

The SF board’s clickety clack sounds worked fine in the other assembly, but the clickety clack sounds still didn’t work in the SF car’s assembly. The sensor only seems to emit a light staticy noise.

So, the problem isn't the RS4 board, but one of the other parts is...

What are you using for a sensor?

I’m using the chuff sensor and magnet by ERR (not the original large magnet and hall sensor) since it’s easier to use for this project.

The plain magnet and reed switch has always worked for me, not sure why it doesn't work for your situation.

I even tried swapping out the power board and R2LC boards to see if it would change. It didn’t. The only component that might be off is the main circuit board.

The only other off thing I noticed was the speaker making a couple sporadic light crackling/popping sounds here and there, but all the other sounds (minus the clickety clacks) function fine and clear.

I'd take a look under the motherboard, the popping noise sounds like a bad connection somewhere.  Maybe one of the connectors had a mangled contact?  Bad solder or broken trace under the motherboard?