G1000 NXi System Maintenance Manual
Page 178
King Air 300 Series
Revision 1
190-00716-N1
Servo Faults and Troubleshooting
Whenever a servo fault occurs, a status message is logged to the corresponding servo control
or monitor maintenance log. This information is also accompanied by a time and date stamp.
An “RTC DATE” entry is made every time a servo is powered on, it is normally not useful for
troubleshooting.
The following is a listing of possible faults that could be reported in a GSA fault log. Faults can
occur in either the monitor board processor or the control board processor, both of which are
contained in the GSA unit.
Monitor Processor
The monitor processor contains the logs that are found in these processors -
2 – Pitch Servo
4 – Roll Servo
6 - Yaw
8 – Pitch Trim Servo
There are two main groupings of faults that can occur in the monitor processor:
The first grouping of faults can occur during the GSA unit pre-flight test (PFT). If there is a fault
during PFT the unit will not be able to transition to normal mode and the only way to clear this
state would be to cycle unit power.
The second grouping of faults can occur during normal mode. These faults generally cause a
removal of power to the GSA and report that a fault has occurred to the GIA.
The Notes column indicates any actions that can be taken to troubleshoot the problem in the
aircraft by the technician. Any faults that are not listed here indicate an internal problem
requiring replacement of the servo. If the items in the Notes column check out ok, replace the
servo.
PFT Faults
MONITOR PFT STEP
NOTES
"INTERNAL COMM FAIL"
This can sometimes be a result of a failure on the other internal
servo board, check faults on the other processor
"UNSW POWER INV"
Check unit power
"MON SOL PWR ON FAIL"
Check unit power and AP Disconnect power
"CTL SOL PWR ON FAIL"
Check unit power and AP Disconnect power
"SOL PWR FAIL"
Check unit power and AP Disconnect power
"CERT DATA
UNINSTALLED"
Upload the certification gain file to the Monitor board
"STRAP CODE
MISMATCH"
Check the connector strap inputs to the unit
Summary of Contents for G1000 NXi
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