JeffreyJ posted:the pod and speaker were tested in the working commodore and both worked. The tether was tested with a VOM and passed. I did NOT try placing the system into conventional mode and testing the sound board. In conventional mode, is the LCRU unit bypassed?
You essentially eliminate the LCRU as a cause by working in conventional mode.
Chuck Sartor posted:Not likely the LCRU. The Commodore tender and the Yellow belly tenders are not wired the same. The Commodore tender has a four prong plug and the C&O has six. While both tenders have the same plugs for the circuit board, they connect to different pins in the tether. I highly suspect the power and ground pins. The guys at Lionel service should be able to supply you with a modified wiring diagram with the correct pin-outs from the six prong plug to the 4 prong plugs. Once you get that figured out, you might be able to use your original PIC and ROM chips for the original soundset.
Chuck, I agree with you that I don't believe it's the LCRU, and that the tenders are not wired the same. One correction though, is that the Vanderbilt has a six-pin tether and the C&O has eight.
The wiring diagrams for the C&O locomotive are here, and the tender here. Scroll down to the last page of each file.
The RS2.5 board gets its power from the black and black/red-striped wires. As you can see, it's a straight pass-through from the locomotive, without going through any electronics. Like Chuck said, start there.
TRW
