Quote Originally Posted by jimkarl View Post
Disconnected phono board r13 line - voltage is present on Phono board (no longer present on main board volume pot) so voltage is coming from phono board. Voltage is present at C12/R20 junction, which I don't understand how that could be, given a brand new 4.7 tant installed.
You're right - with a good capacitor and a good resistor for C12/R20 there should be no DC. That means either a dodgy cap or the 100k resistor has gone open circuit. Measuring the resistor should be easy enough.
Actually, there's one other possibility - a DC path in parallel with the capacitor caused by dirt/dampness or some other contaminant on the circuit board in the vicinity of the capacitor.