Garmin GNC 420AW, Installation Manual

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400W Series Installation Manual Page 6-7
190-00356-02 Rev. G
Alert Text Possible Cause Solution
•
Improper antenna installation or
coax routing
•
Check GPS antenna
installation, connections, and
cable routing. The GPS
antenna must be mounted on
the top of the aircraft.
•
Antenna shaded from satellites
•
Make sure the aircraft is clear
of hangars, buildings, trees,
etc.
Loss of integrity — cross-check
NAV
•
RF interference at 1575.42 MHz
from VHF COM.
•
Move GPS antenna further
from the COM antenna, Add a
1575.42 MHz notch filter in
COM coax. Fix or replace the
COM. Disconnect the ELT
antenna coax to check for
possible re-radiation.
Low Battery - Unit Needs Service
•
Time data may have been lost
due to a memory battery failure.
•
Replace the battery (refer to
section 8.4)
MAIN processor requires service
•
The 400W-series unit has
detected a failure in the main
system processor.
•
Contact Garmin technical
support.
No altitude input is being
received
•
No altitude data is being
received from RS-232
(Serializer: Icarus, Rosetta or
Shadin) or grey code inputs.
•
Refer to Table 6-1 “RS-232
device is not communicating
with the
GPS 400W/GNS430W”
No basemap data available
•
The 400W-series unit has
detected a failure in the built-in
basemap (land data) memory.
Land data does not appear on
the Map Page. Other unit
functions continue to work
normally.
•
Contact Garmin technical
support to reload the basemap
data
Not receiving input data on 429
Channel #1 or #2
•
No data has been received on
the ARINC 429 channel #1
connection for a period
exceeding five seconds.
•
Refer to Table 6-1 “ARINC 429
device is not receiving data
from the GPS 400W/GNS
430W”
Not receiving input data on 232
Channel #(1 through 5)
•
No data has been received on
one (or more) of the RS-232
channel connections for a
period exceeding ten seconds.
•
Refer to Table 6-1 “RS-232
device is not communicating
with the 400W/430W”
•
Check for proper configuration
•
Check the wiring
Not receiving traffic data
•
No traffic data is being received.
•
Contact Garmin technical
support.
OBS key stuck
•
The OBS key is stuck in the
enabled (or pressed) state. Try
pressing the OBS key again to
cycle its operation.
•
Contact Garmin technical
support.