Furuno GP-7000F - Manual (Page 118)

11. MAINTENANCE & TROUBLESHOOTING
11-4
Sounder troubleshooting
If … Then …
check if STOP is not selected at
PICTURE ADVANCE on the
SOUNDER menu.
check for loosened transducer
connector.
picture does not move although marks
and characters appear
on SOUNDER SETUP menu, set
TRANSMISSION POWER to High.
zero line does not appear though the
picture appears
the picture is shifted. Confirm shift
setting.
check gain setting, if using manual
operation.
marine life or air bubbles may be
clinging to transducer face.
picture sensitivity is too low
on SOUNDER SETUP menu, set
TRANSMISSION POWER to High.
the depth indication is not displayed
adjust gain and range to display the
bottom echo in reddish brown, if you
are using the manual operation.
if no noise appears after turning the
engine off, the engine interference is
suspected. Call your dealer.
check the ground.
noise or interference shows on the
display
other video sounder of the same
frequency as yours may be operating
near you.
temperature of the water on the water
temperature graph is wrong.
check that sensor cable is tightly
fastened.