Garmin G1000 Nxi System Maintenance Manual page 157

MFD1 RS-232
Channel LRU
CHNL 1 GCU 477
G1000 NXi System Maintenance Manual
King Air 300 Series
190-00716-N1
Indicator Status
Green MFD1/GCU 477 data path is functioning correctly.
MFD1/GCU 477 data path is not functioning correctly.
•
Verify GCU 477 is powered on.
o If GCU 477 will not power on, remove unit and
Red
•
Load MFD1 and GCU 477 configuration files.
•
Check the MFD1/GCU 477 interconnect wiring for
faults.
•
Replace GCU 477.
Replace MFD if problem remains.
MFD1/GCU data path functionality is unknown. Reload
Amber
MFD1 configuration file.
verify power and ground are present at the
GCU connector.

If power or ground is not present,
troubleshoot aircraft wiring for faults.

If power and ground are present,
replace GCU 477.
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