190-00692-00 Rev. B Garmin G1000 Pilot’s Guide for Piper PA32 4-39AUDIO PANEL AND CNS4.7 ABNORMAL OPERATIONAbnormal operation of the G1000 includes equipment failures of the G1000 components and failure ofassociated equipment, including switches and external devices.STUCK MICROPHONEIf the push-to-talk (PTT) Key becomes stuck, the COM transmitter stops transmitting after 35 seconds ofcontinuous operation. An alert appears on the PFD to advise the pilot of a stuck microphone.The COM1 MIC or COM2 MIC Key Annunciator on the Audio Panel flashes as long as the PTT Key remainsstuck.Figure 4-47 Stuck Microphone AlertCOM TUNING FAILUREIn case of a COM system tuning failure, the emergency frequency (121.500 MHz) is automatically tuned inthe radio in which the tuning failure occurred. Depending on the failure mode, a red X may appear on thefrequency display.Figure 4-48 COM Tuning FailureEmergency ChannelLoaded AutomaticallyAUDIO PANEL FAIL-SAFE OPERATIONIf there is a failure of the Audio Panel, a fail-safe circuit connects the pilot’s headset and microphone directlyto the COM1 transceiver. Audio will not be available on the speaker.REVERSIONARY MODEThe red DISPLAY BACKUP Button selects Reversionary Mode for both displays. Reversionary Modeoperation displays flight and engine information on both the PFD and MFD, in case of display failure.See the System Overview Section for more information on the DISPLAY BACKUP Button.Figure 4-49 Reversionary Mode Button
