Did you manage to figure out how to use a multi-meter to measure frequency on the 820-00165 board? I am struggling with the exact same problem and the same chip U1900, pin 12. Thank you.
On Nov 26, 2017, you wrote: "... I can't get anything other than a default 60Hz
..."
On Nov 26, 2017, you wrote: "... I can't get anything other than a default 60Hz