Morning update:
Separating the ribbon cable had no effect, so I started poking around with my continuity probe, found that the output and ground were shorted. I disconnected the board from the switch, and confirmed the prob is on the board, not the switch. Working on it now...
Separating the ribbon cable had no effect, so I started poking around with my continuity probe, found that the output and ground were shorted. I disconnected the board from the switch, and confirmed the prob is on the board, not the switch. Working on it now...