System Maintenance Manual

Page 5-40 G1000/GFC700 System Maintenance Manual – C90A/C90GT/C90GTi King Air
Revision F 190-00682-01
5.6.5.1 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
disconnect of power to the GSA and report to the GIA that a fault has occurred.
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.