Garmin GNC 420AW Installation Manual - page 124
Page 6-2
400W Series Installation Manual
Rev. E
190-00356-02
Table 6-1. Troubleshooting Guide
Problem Possible
Cause
Solution
The sidetone level is
too low or too high.
•
Wrong type of headsets, or
level needs adjustment.
•
If necessary, adjust the sidetone level.
Sidetone adjustment is found on the
COM Setup page.
OBS Resolver won’t
calibrate.
•
Incompatible resolver or
improper connection.
•
Check the resolver specifications and
wiring.
OBS indication on
400W Series unit
does not agree with
OBS setting.
•
400W Series unit resolver input
not calibrated correctly.
•
Resolver has not been
calibrated.
•
Check wiring and calibration.
•
ARINC 429 input port speed
not correct
•
Check ARINC 429 input port speed
setting for port that device is
connected to and verify that the speed
is correct for that device.
400W Series unit is
not receiving
heading from
compass system
(ARINC 429
heading input used)
•
Wiring connections are
incorrect.
•
Check wiring.
•
400W Series unit does not have
a position or flight plan
entered.
•
Acquire GPS position and enter a
flight plan.
•
400W Series unit ARINC 429
output not configured correctly.
•
Check ARINC 429 output port setting
for port that autopilot is connected to.
•
ARINC 429 output port speed
not correct.
•
Check ARINC 429 output port speed
setting for port that autopilot is
connected to and verify that the speed
is correct for autopilot.
•
Wiring connections are
incorrect.
•
Check wiring. Must be connected to
main GPS 429 output.
Autopilot is not
getting GPSS/Roll
Steering data from
the 400W Series
unit (ARINC 429
Roll Steering used)
•
Certain autopilots require
groundspeed for GPSS to be
enabled.
•
Ensure that groundspeed is provided
if required by the autopilot.
•
Desired RMI source has not
been selected.
•
Check the OBI source selection on
the Main CDI/OBS Config page.
RMI pointer does
not indicate
correctly
•
Wiring connections are
incorrect.
•
Check wiring.
•
Incorrect configuration.
•
Check the DME Channel Mode on
the VOR/LOC/GS CDI page.
Tuning data not
updating DME
•
Wiring connections are
incorrect.
•
Check wiring.