The thing that seems to control whether I get "nothing" on the arduino serial port from the Betz board, or whether I get "something" on the arduino serial port from the Betz board, is the position of that SMD 2 pole switch.

When it is in the down/right position, I get nothing.
When it is in the up/left position, I get something.

When I get "something" it is either:
- The expected text mixed with garbage characters if I do NOT have power applied to the Betz board USB port via a USB cable.
- Fully perfect text if I DO have power applied to the Betx board USB port via a USB cable.

In the latter state, with the Betz USB port being supplied power via the USB cable the 3v3 pin reads about 2.5 volts.
In the former state, with the Betz USB port NOT being supplied power, the 3v3 pin reads different voltages depending on the position of the switch. Down/right: 2v or less, Up/left: 2.5v.