General Troubleshooting; Table 5-1 General Troubleshooting Guide - Garmin GFC 600H Maintenance Manual

5.1 General Troubleshooting

Table 5-1 describes possible symptoms associated with the Garmin GFC 600H FCS and provides
corresponding actions for troubleshooting. After completing the recommended action, perform the
appropriate return-to-service procedure in accordance with Section 1. If any system messages persist after
performing the associated troubleshooting actions, contact Garmin for service.
NOTE
For cycling power of the GFC 600H system, wait until the display has completely turned
off prior to re-energizing the system.
Symptom
The FCS will not engage
(i.e., FCS LED on GMC 605H
does not illuminate green).
GMC 605H display is blank.
PFT will not pass (displayed
on GMC 605H or GDU if
installed).
Servos will not engage ("P",
"R", or "Y" will not display on
GMC 605H when FCS button
is pressed).
190-02081-03
Rev. 3

Table 5-1 General Troubleshooting Guide

• Verify that PFT has passed. Power cycle the GFC 600H by cycling
the FCS circuit breaker. This will cause PFT to restart.
• Ensure the GMC 605H, GFS 83, GSU 75H/GRS 79H, and
GMU 44( ) connectors are securely mated to the units.
• Ensure wiring is correct.
• Ensure the FCS DISC and FTR switches on cyclic are not stuck or
shorted.
• Verify wiring of FCS DISC and FTR from FCS circuit breaker
through switch to the GMC 605H and GFS 83.
• Ensure all post-installation calibration procedures (Section 7.7)
have been successfully completed.
• Ensure the system is powered.
• Ensure the GMC 605H connectors are securely mated to the unit.
• Ensure the GMC 605H wiring is correct.
• Ensure FCS and ADC circuit breakers are closed.
• Ensure the GMC 605H, GFS 83, GSU 75H, and GMU 44( )
connectors are securely mated to their respective units.
• Ensure wiring is correct.
• Ensure the GFS 83 servo strapping for the configured control axis
is correct.
• Ensure servos were reinstalled in the correct location if removed
from aircraft. If they were not, servo calibration and strapping must
be performed again.
• Ensure control linkages and servo connections are secure without
play.
• Ensure the FCS DISC and FTR switches on cyclic are not stuck or
shorted.
• Verify wiring of FCS DISC and FTR from circuit breaker to switch to
the GMC 605H and GFS 83.
• Ensure all post-install calibration procedures have been run and
passed for the GMC 605H, GFS 83, and GSU 75H/GMU 44( ).
• Verify that PFT has passed. Power cycle the GFC 600H by cycling
the FCS circuit breaker. This will cause PFT to restart.
• Contact Garmin.
GFC 600H HFCS Part 27 STC Maintenance Manual
Recommended Action
Page 5-2