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Page 5-72
G1000 System Maintenance Manual
Rev. A
190-00903-00
5.1.7.4 NAV
Symptom Recommended
Actions
Weak NAV receiver
•
Set up a NAV/COM Ramp Test Set to radiate a test signal.
•
Swap GIA1 and GIA2, reconfigure both GIA’s to their new
locations, to verify location of problem.
−
If problem follows unit, replace GlA.
−
If problem does not follow unit, check NAV antenna,
coupler, and cabling for faults.
5.1.7.5 Glideslope
Symptom Recommended
Actions
Weak G/S Receiver
•
Set up a NAV/COM Ramp Test Set to radiate a test signal.
•
Swap GIA1 and GIA2, reconfigure both GIA’s to their new
locations, to verify location of problem.
−
If problem follows unit, replace GlA.
−
If problem does not follow unit, check NAV antenna,
coupler, and cabling for faults.
5.1.7.6 GDC 74B
Symptom Recommended
Actions
Altitude is different than standby
altimeter
•
Perform a pitot/static check (see applicable airframe specific
maintenance manual for procedure). Allow the GDC to warm
up for fifteen minutes before checking accuracy, per Garmin
Service Advisory 0606.
•
Determine which instrument is outside limits and recalibrate or
replace. Note: Both units may individually be in spec but show
a difference in altitude. Do not return a GDC to Garmin for
service if not outside limits.
•
If GDC is outside limits, recalibration may be performed in
accordance with Garmin Service Bulletin 0720, Section 2.7.3.
GDC 74B Config file does not
load.
•
Replace GDC 74B config module.
•
If problem persists, replace GDC 74B config module wire
harness.
