OSD works, doesn't tune channels although the OSD says it does. When I introduce the cable connector to the tuner connector the snow changes patterns as if it is receiving some signal from the cable. Snow is different on the 2-13 channel tier leading me to believe there is a change in the tuning voltage.
It would seem from this simple test that the varactor diode is shot in the tuner module but would rather just replace the entire tuner.
Is this a fair diagnosis?