Garmin GTN 750 Cockpit Reference Guide - Page 45

Message Description Action CDI/HSI FLAGMain lateral/vertical flag on CDI/HSI is inoperative. Main Lateral Superflag or Main Vertical Superflag output has been turned off due to an over-current condition. Verify course guidance is valid and correct by crosschecking with the GTN on-screen CDI and other navigational equipment. Contact dealer for service. COM RADIOCOM radio needs service. COM radio is reporting Contact dealer for service. that it needs service. The COM radio may continue to function. COM RADIO- COM radio is not Press and hold the volume COM radio may be communicating properly knob or the external COM inoperative. with the system. remote transfer (COM RMT XFR) switch, if installed - this will force the COM radio to 121.5 MHz. Contact dealer for service. COM RADIOCOM overtemp or undervoltage. Reducing transmitter power. COM radio is in overtemp or undervoltage mode and transmitting power has been reduced to prevent damage to the COM radio. Radio range will be reduced. Decrease length of COM transmissions, decrease cabin temperature and increase cabin airflow (especially near the GTN). Check aircraft voltage and reduce electrical load as necessary. Contact dealer for service if this message persists. COM RADIO- COM radio is locked to COM locked to 121.5 121.5 MHz. MHz. Hold remote COM transfer key to exit. The external COM remote transfer (COM RMT XFR) switch has been held and the COM radio is tuned to 121.5. To exit this mode, hold the COM remote transfer (COM RMT XFR) switch for two seconds. Messages 190-01007-04 Rev. B GTN 725/750 Cockpit Reference Guide (CRG) 39