Humminbird SINGLEBEAM 405SX Operation Manual page 29

MAINTENANCE
MAINTENANCE/TROUBLESHOOTING
2. There is no transducer detected.
The 405SX has the ability to detect and identify that a transducer is connected.
First, ensure that an appropriate transducer connector is positioned correctly in
the connector holder, and that the unit is fully seated on the mount.
Second, inspect the transducer cable from end to end for breaks, kinks, or cuts in
the outer casing of the cable. Also ensure the transducer is fully submerged in
water. If the transducer is connected to the unit through a switch, temporarily
connect it directly to the unit and try again. If none of these items identifies an
obvious problem, the transducer itself is probably the problem. Be sure to include
the transducer if returning the unit for repair.
3. There is no bottom reading visible on the display.
There are a number of possible causes for this condition. If the loss of bottom
information occurs only at high boat speeds, the transducer needs adjusting. If the
digital depth readout is working but there is no bottom visible on-screen, it is possible
the depth range has been adjusted manually to a range lower than what is needed
to display the bottom. Also, in very deep water, it may be necessary to manually
increase the sensitivity setting to maintain a graphic depiction of the bottom.
If you are using a transducer switch to connect two transducers to the 405SX,
ensure the switch is in the correct position to connect a transducer that is in water.
(If a trolling motor transducer is selected and the trolling motor is out of water, no
sonar information appears.)
If none of the above solve the problem, inspect the transducer cable from end to
end for breaks, kinks, or cuts in the outer casing of the cable. If the transducer is
connected to the unit through a switch, temporarily connect it directly to the unit
and try again. If none of these items identifies an obvious problem, the transducer
itself may be the problem. Be sure to include the transducer if returning the unit
for repair.
4. When in very shallow water, I get gaps in the bottom reading
and inconsistent digital depth indication.
The 405SX will work reliably in water 2' or deeper. The depth is measured from
the transducer, not necessarily from the surface.
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