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Aviation Alerts and Advisories

Service Letter 21127: GTN™ Xi Series System Software Loader Images


        ModelAppliance P/N
GTN 625Xi – 011-04629-00
GTN 635Xi – 011-04630-00
GTN 650Xi – 011-04631-( )
GTN 725Xi – 011-04632-00
GTN 750Xi – 011-04634-( )


The GTN Xi Series System Loader Images fail to load software on some GTN Xi units. When this occurs, the GTN Xi will either not power on when the software loader card is installed in the GTN Xi, or the GTN Xi will display a ‘COM Needs Service’ message in normal mode after the COM software appears to have been installed successfully.


GTN Xi Series System Loader Images have been revised and updated on the Garmin website. It is strongly recommended to download the latest GTN Xi Series System Loader Image from the Garmin website.

Service Letter 21127 Rev A