70
MX 420 Installation and Service Manual
Problem
Diagnosis
No response: (Black LCD display and no
traffic light)
No external power supply
Check supply voltage
Check for reverse polarity
Check wire installation
Check if external fuse is blown
No keyboard response or partial keyboard
response
Corrupted memory
faulty keyboard
faulty processor
Return the unit for repair
Battery low alarm
External battery low
Check power supply voltage and
installation
No position update; won’t track satellites
(Red traffic light blinking for more than 10
minutes)
Jamming by other on- board or adjacent
transmitters
Faulty antenna or antenna cable
Relocate GPS antenna
Connect the MX421 power directly to the
external 12 VDC supply.
Replace antenna
Return the unit for repair
No position update; tracking satellites
(Red traffic light solid all the time)
DGPS mode set to
DGPS Only
and no
corrections are being received
GPS satellite signals weak (satellites
dropping in and out)
Check maximum cable length restrictions
and cable condition (for weak satellite
signal condition)
Return the unit for repair
All data lost at power up
Backup battery is dead
Replace the internal backup battery
No DGPS update; not tracking beacon
station
DGPS mode set to
Off,
so no corrections
are being received.
Station Select
is set to
Manual.
Faulty antenna
No data output to peripheral equipment
NMEA output data not configured
Wrong NMEA version
Wrong output rate, or format
Wrong electrical standard
Too many data sentences turned on
(throughput overflow)
More than one NMEA
talker
on the circuit
Faulty port
The MX420 requires the user to enable
NMEA
Return the unit for repair
Summary of Contents for MX420
Page 1: ...Installation Service Manual MX420 Navigation System ...
Page 5: ......
Page 8: ...1 MX 420 Installation and Service Manual List of Components SECTION 1 LIST OF COMPONENTS ...
Page 9: ...MX 420 Installation and Service Manual List of Components 2 ...
Page 15: ...MX 420 Installation and Service Manual List of Components 8 ...
Page 17: ...MX420 Installation and Service Manual Technical Specifications 10 ...
Page 24: ...17 MX420 Installation and Service Manual SECTION 3 MECHANICALAND INSTALLATION DRAWINGS ...
Page 25: ...18 MX420 Installation and Service Manual ...
Page 32: ...25 MX420 Installation and Service Manual SECTION 4 ELECTRICALINSTALLATION DRAWINGS ...
Page 33: ...26 MX420 Installation and Service Manual ...
Page 49: ...42 MX420 Installation and Service Manual ...
Page 57: ...50 MX 420 Installation and Service Manual SECTION 5 INSTALLATION NOTES ...