System Maintenance Manual

G1000/GFC700 System Maintenance Manual – C90A/C90GT/C90GTi King Air Page 5-9
190-00682-01 Revision F
MFD1 RS-232
Channel LRU Indicator Status
CHNL 1 GCU 475
MFD1/GCU 475 data path is functioning correctly.
MFD1/GCU 475 data path is not functioning correctly.
• Verify GCU 475 is powered on.
o If GCU 475 will not power on, remove unit and
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 475.
• Load MFD1 and GCU 475 configuration files.
• Check the MFD1/GCU 475 interconnect wiring for faults.
• Replace GCU 475.
Replace MFD if problem remains.
MFD1/GCU data path functionality is unknown. Reload MFD1
configuration file.