No gain control on 588

[rolmops]

i have a 2 year old Furuno 588 hooked to an Airmar tr260 transducer. It works fine as long as the gain setting is on fishing or cruising. When I
switch the gain to manual it does not react at all . I can turn the knob in either direction and the gain remains exactly the same. There is not really a 10 position rotation at all . It just turns around more than full circle. Is there something I am doing wrong or is the board defective?

 

[Deep Blue]

rolmops,

You should be able to control the FCV588's Gain in manual mode. I'd contact your local dealer to have the FCV588 checked out.

- Deep Blue

 

[FishTech]

Press the Gain Knob.
Use the up or down arrows to highlight Off.
Press the Enter button.
Then when looking at the fish finder image you should be able to rotate the knob and see it adjust gain in increments of 0.1
You are correct in that it is not a limited rotation.
If these steps do not work, I would do as Deep Blue suggests above.