@Vernon Barry posted:I'm trying to catch back up here but what is the exact model number this board came from?
It's either one of 2 scenarios, you might need to wire the smoke switch up and it be in the closed position, or yes, possible the board they locked out that feature in the firmware.
The board should have sikscreen tiny annotations beside the pins of the connectors on the backside showing the switch input connector and the pin for smoke.
Vernon- here's the parts diagram for the original loco.
https://www.lionelsupport.com/search?keywords=6-84710
The pin out on the board is
+5v
SND
SMK
I/O
GND
As I wrote, I tried all logical combinations and other than the 5vdc, nothing worked.
Bob