Troubleshooting; Diagnostics - Furuno LS-4100 Operator's Manual

3.6 Troubleshooting

The table below provides basic
troubleshooting procedures which the
user may follow to restore normal
operation.
Troubleshooting table
If...
neither echo nor
fixed range scale
appears
no echo appears
but the fixed
range scale
appears
echo appears but
no zero line
sensitivity is low
there is extreme
interference or
noise
the speed/water
temperature
readout is
unrealistic or not
present
the position
readout is
unrealistic or not
present
Then check ...
battery voltage.
fuse.
power cable.
if display advance
speed is set to "Stop."
transducer plug
transducer cable
if range shifting is set
to "0."
gain setting.
if air bubbles or marine
life is clinging to the
transducer face.
if sediments are
present in the water.
if the bottom is too soft
to return an echo.
if the transducer is too
close to the engine.
if the unit is properly
grounded.
if other echo sounders
of the same frequency
as own are being
operated nearby.
sensor plug.
the connection
between sounder and
navigator.
navigator.

3.7 Diagnostics

If you feel your unit is not working
properly, conduct the diagnostic test to
find the problem. If you cannot restore
normal operation, contact your dealer
for advice.
1. Turn on the power while pressing the
[MENU/ESC] key. Continue pressing
the [MENU/ESC] key until the
Installation menu appears.
Installation Menu
Installation menu
2. Press▼ to choose TEST.
3. Press ► to start the test.
Test display
22
ROM : OK
RAM : OK
NMEA :
Temp : 68.2 F
Speed : 10.0km/h
Power : 12.4 V
Body : 39 C
Program No. 0252318-01.**
Push [MENU] 3 times to exit.
** = Program version no.