Furuno color video plotter GD1720C - Manual (Page 214)

8. MAINTENANCE, TROUBLESHOOTING
8-5
8.5.4 Sounder
Requires Network Sounder ETR-6/10N/30N.
Sounder troubleshooting
If… But… Then…
you selected a sounder
display with the DISP key
picture does not appear • check that the network
sounder’s signal cable is firmly
fastened.
• Check that sounder source is
correct.
• check that the network sounder
is plugged in. The LED on the
network sounder should flash
every second.
marks and characters
appear
picture does not appear • check for loosened transducer
connector.
the picture appears zero line does not appear • the picture is shifted. Confirm
shift setting.
picture sensitivity is too low — • check gain setting, if using
manual operation.
• marine life or air bubbles may
be clinging to transducer face.
• bottom may be too soft to
return a suitable echo.
the depth indication is not
displayed
— • adjust gain and range to display
the bottom echo (in reddish
brown), if you are using the
manual sounder mode.
noise or interference shows
on the display
— • check to be sure the transducer
cable is not near ship’s engine.
• check the ground.
• other video sounders of the
same frequency as yours may
be operating near you.
the water temperature graph
appears
data is wrong • check that sensor cable is
tightly fastened.