The 470K resistance is coming from the Phone socket.
The circuit will read the type of Circuit it is testing either there is a socket on it (470k) or It is a open circuit or a Short
If an Open Circuit or Short can’t be done or is a problematic to design i will settle with it just detecting the resistor.
The circuit will read the type of Circuit it is testing either there is a socket on it (470k) or It is a open circuit or a Short
If an Open Circuit or Short can’t be done or is a problematic to design i will settle with it just detecting the resistor.