Navico Corus Nav System

[timj]

A friend has this system running well except that the log no longer gives any speed read out.

When he removes the sender from the hull and turns the impeller by hand the speed indicates on the display unit.

But when he reinstalls in back in the hull there is no reading.

The sender is not obstructed in any way when in position in the hull.

We think it must be an electronic issue but very puzzling!

Any thoughts appreciated. These units are no longer on the market so zero interest here in NZ in any repair support.