NorthStar MX500 Operator's & Installation Manual page 240

Installation Manual
Problem
No response: (Black LCD display and no
traffic light)
No keyboard response or partial keyboard
response
Battery low alarm
No position update; won't track satellites
(Red traffic light blinking for more than 10
minutes)
No position update; tracking satellites
(Red traffic light solid all the time)
All data lost at power up
No DGPS update; not tracking beacon
station
No data output to peripheral equipment
226
Diagnosis
No external power supply
Check supply voltage
Check for reverse polarity
Check wire installation
Check if external fuse is blown
Corrupted memory
faulty keyboard
faulty processor
Return the unit for repair
External battery low
Check power supply voltage and
installation
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
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
Backup battery is dead
Replace the internal backup battery
DGPS mode set to Off, so no corrections
are being received.
Station Select is set to Manual.
Faulty antenna
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
Installation Notes
Version 3.0