5 8.5.4 sounder – Furuno NAVNET 1724C User 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. 
