FISH 4100 Installation and Operation Manual NAVMAN 23
To stop problems from electrical noise, try:
- rerouting the power and transducer
cable(s) away from the boat’s other
- routing the unit's power cable directly to the
battery instead of through a fuse block or
4. Bottom is not displayed:
a) The fishfinder may have Manual Range
selected and the depth may be outside the
range value selected. Either change the
fishfinder to Auto Range or select another
depth range - see section 3.8.
b) The depth may be outside the fishfinder’s range.
While in Auto Range, the display unit will flash
the last depth displayed, then display “--.-” to
indicate that there is no bottom detected. A
display of the bottom should reappear when it is
shallower than 180m (600ft).
5. The bottom is displayed too far up the screen:
The fishfinder may have Manual Range
selected and the selected Range value is too
high for the depth. Either change the fishfinder
to Auto Range or select another depth range -
see section 3-8.
6. Bottom echo disappears or erratic digital
reading while the boat is moving:
a) Ensure the back of the bottom surface of the
transducer is slightly lower than the front and
the front is as deep in the water as possible in
order to minimize the generation of bubbles
through cavitation. See the Transducer
Installation Guide for more information.
b) The transducer may be in turbulent water. Air
bubbles in the water disrupt the echoes
returned, interfering with the fishfinder’s ability
to find the bottom or other targets. This often
happens when the boat is reversed. The
transducer must be mounted in a smooth flow
of water in order for the fishfinder to work at all
c) Electrical noise from the boat’s motor can
interfere with the fishfinder. Try some
suppression spark plugs.
7. If the fishfinder beeps when turned on but
nothing is displayed:
The fishfinder may be operating, but the
contrast settings may have been set too high
or low. Power off the fishfinder. Then hold
and press to reset the fishfinder to the
default contrast setting.
8. The wrong language is displayed:
See section 2.
9. The message "NO TRANSDUCER DETECTED.
ENTER SIMULATION MODE?" appears when you
turn the unit on:
a) Check to see that the blue transducer
connector is plugged into the top connector
(with the blue nut) on the rear of the display
b) Check the cable connectors are securely
plugged in and the blue collars are is locked in
place. The collars must be secure for water
c) Check that the plugs are clean and free of
water or anything that may short deteriorate the
quality of the connection. Inspect the
transducer cable from end to end for damage
such as cuts, breaks, stretched or squashed