Garmin G1000 Nxi System Maintenance Manual page 191

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.
MONITOR PFT STEP
"INTERNAL COMM FAIL"
"UNSW POWER INV"
"MON SOL PWR ON FAIL"
"CTL SOL PWR ON FAIL"
"SOL PWR FAIL"
"CERT DATA
UNINSTALLED"
"STRAP CODE
MISMATCH"
G1000 NXi System Maintenance Manual
King Air 300 Series
190-00716-N1
PFT Faults
NOTES
This can sometimes be a result of a failure on the other internal
servo board, check faults on the other processor
Check unit power
Check unit power and AP Disconnect power
Check unit power and AP Disconnect power
Check unit power and AP Disconnect power
Upload the certification gain file to the Monitor board
Check the connector strap inputs to the unit
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