Gtn Configuration And Testing; Com Configuration Page (Gtn 635/650/750 Only); Connector Engagement Check - Garmin GTN 6 Series Maintenance Manual

6.3 GTN Configuration and Testing

This section covers the configuration and checkout procedures that must be completed when a GTN is
replaced with an equivalent unit. The steps provided in this section are only applicable for replacement of
an equivalent GTN unit (i.e., 750 for 750, 625 for 625, etc.). If wiring updates are needed, or the
configuration module is being replaced simultaneously, refer to GTN 6XX/7XX Part 27 AML STC
Installation Manual for installation instructions.
For instructions on feature enablement, refer to Section 3.3.4. If the configuration module is not replaced,
the enabled features will be retained upon replacing the GTN.
Ground checks of the GTN require the GTN to be powered-up in Configuration mode as described in
Section 3.3.
6.3.1

COM Configuration Page (GTN 635/650/750 Only)

Select the COM Configuration page from the GTN Setup page. These values are set at the factory and
rarely require calibration.
To enable or disable the COM radio, touch the COM key to toggle between Enabled and Disabled. The
COM radio defaults to the enabled state.
Review the COM configuration settings on the GTN and compare them against the GTN Configuration
Log that is retained with the rotorcraft permanent record. A blank copy of the GTN Configuration Log
form may be found in Appendix A of this document. If any of the settings differ from the checkout log,
update the settings to the correct value. For information regarding individual settings, refer to
GTN 6XX/7XX Part 27 AML STC Installation Manual.
6.3.2

Connector Engagement Check

Prior to configuration and checkout of the GTN, perform a connector engagement check.
1. Remove power from the GTN.
2. Slide the GTN straight into the rack until it stops about 1 inch short of the fully seated position.
3. Insert a 3/32" hex drive into the unit retention mechanism access hole at the bottom of the unit face
and turn the tool clockwise while pressing the bezel until the unit is firmly seated in the rack.
4. With the GTN seated, re-apply power.
5. Insert the hex drive into the unit retention mechanism access hole.
6. Turn the tool counterclockwise to back out the retention mechanism. Ensure that three (3)
complete revolutions of the hex screw can be performed without a red "X" indication or loss of
power to the GTN.
NOTE
If power is lost or the red "X" condition occurs with fewer than three (3) turns, ensure
there are no obstructions to the unit fully seating in the rack. The mounting rack may need
to be moved aft (toward the pilot) such that the rotorcraft panel does not obstruct the unit
from properly engaging in the rack.
7. Remove power from the unit.
8. Re-seat the GTN as described in step 3.
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GTN 6XX/7XX Part 27 AML STC Maintenance Manual
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