FM-4850 Operator’s Manual
MAINTENANCE AND TROUBLE
SHOOTING
The sound is not
emitted from the
speaker.
Step 1 Check that the cable
(Red & Black) is
physically connected.
Step 2 Check whether the
speaker cable is broken
or short-circuited.
Transmissions
are always on
low power even
when high
power is
selected.
Check the antenna or test the
radio with another antenna.
The icon or
appears on
the home
screen.
Too high or too low
power supply
voltage
Confirm that the connected power
supply voltage is within 10.8 to
15.6 VDC.
Your position is
not displayed.
Check the NMEA2000 or
NMEA0183 cable connection.
Setting of the
GNSS receiver
Choose the proper information to
check:
If the NMEA2000 or
NMEA0183 cable is
connected, make sure that
the output of the cable is
valid.
If the NMEA2000 or
NMEA0183 cable is not
connected, make sure that
the internal GNSS module is
enabled and nothing blocks
the top of the radio unit.
The radio unit
displays "PLL
UNLOCK".
The phase lock
loop not working
Restart the radio. If the problem
is not fixed, please contact your
dealer.
Output power
reduced to low
Power is
automatically
reduced to protect
Wait until the unit cools.