27FISH 4200 Installation and Operation Manual
This troubleshooting guide is written with the
assumption that the user has read and understood
the relevant sections in this manual.
It is possible in many cases to solve difficulties
without having to send the display unit back to the
manufacturer for repair. Please follow this
troubleshooting section before contacting the
nearest NAVMAN dealer.
There are no user serviceable parts. Specialised
methods and testing equipment are required to
ensure that the display unit is reassembled correctly
and is waterproof. Users who service a NAVMAN
fishfinder themselves will void the warranty.
Repairs to the FISH 4200 may only be carried out by
a service centre approved by NAVMAN NZ. If the
display unit must be sent into a service centre for
repair, it is essential to send in the transducer(s) at
the same time.
More information can be found on our Website:
1. The fishfinder won't turn on:
a) NAVMAN fishfinders are designed to operate
on 12 volt battery systems, where the voltage
may vary from 10 to 16.5 volts. If an excessive
voltage is supplied to the unit, a resettable fuse
will be tripped, turning the display unit off.
b) Check that the power cable LT connector at
the back of the display unit is securely plugged
in and the collar is locked in place. The collar
must be secure for watertight connection.
c) Measure the battery voltage while the battery is
under load - turn on some lights, radio, or other
electrical equipment connected to the battery. If
the voltage is less than 10 volts:
- the battery terminals or wiring on the
terminals may be corroded.
- the battery may not be charging correctly or
may need replacing.
d) Inspect the power cable from end to end for
damage such as cuts, breaks, or squashed
e) Ensure that the red wire is connected to the
positive battery terminal and the black wire to
the negative battery terminal. If wired for the Auto
Power option, ensure the yellow wires are
connected to ignition circuit. Also check the boat's
main switch circuit. See section 5-4.
f) Check for corrosion on the power cable LT
connector and clean or replace if required.
g) Check fuses that are placed in line with the
power cable. A fuse can be blown despite
appearing to be good, or the fuse may be
corroded. Test the fuse or replace it with a fuse
known to be good.
2. The fishfinder won’t turn off:
The fishfinder may have been wired with the
Engine Hours feature enabled. In this case, the
fishfinder cannot be turned off while the ignition
power is on. See Auto Power Wiring in section
3. The fishfinder operates erratically:
a) Check that the transducer does not have debris
(e.g. weed, plastic bag) caught around it.
b) The transducer may have been damaged
during launching, running aground, or running
underway with debris etc. If the transducer has
been impacted, it may have been kicked up on
the bracket. If it is not physically damaged,
reset the transducer back to its original
postion. See the Transducer Installation Guide
for more information.
c) When in water less than 2 feet (0.6 m) the
bottom and depth readings may become
inconsistent and erratic. This depth is
measured from the transducer and does not
allow for any keel offset setting.
d) Manual Gain may be set too low, which may
cause weak bottom echo, or no fish signals. If
Auto Gain is disabled try increasing the gain.
e) 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 minimise the generation of bubbles
through cavitation. See the Transducer
Installation Guide for more information.
f) Check the transducer and power cable LT
connectors at the back of the display unit are
securely plugged in and the collar is locked in
place. The collar must be secure for watertight
g) Inspect the transducer and power cables from
end to end for damage such as cuts, breaks or
h) Ensure there is not another fishfinder or depth
sounder turned on, which may interfere with
the FISH 4200.
i) Electrical noise from the boat's engine or an
accessory may be interfering with the
transducer(s) and/or the NAVMAN fishfinder.
This may cause the fishfinder to automatically
decrease the gain unless using Manual Gain.
The fishfinder thus eliminates weaker signals
such as fish or even the bottom from the
display. This may be checked by switching off
other instruments, accessories (e.g. bilge
pump) and the motor until the offending device
Appendix B - Troubleshooting