Troubleshooting Avidyne IFD 440 transmit problem

[NotarPilot]

While flying today I began experiencing a new problem with one of my two IFD 440s. The bottom unit began transmitting intermittently on its own, sometimes a bit rapidly. At one point the problem unit seemed to shut down the radio and an annunciation said “TX stuck open” on the screen.

My audio panel was set to transmit on the top unit so I don’t think it’s the wiring or the TX switch on the yoke as the switch is only about 3 years old.

I want to do some troubleshooting so I want to swap the units to see if the problem follows the unit or stays on the bottom tray. Does anyone know what size Allen wrench is needed to unscrew the unit.

Second, would there be any problems by swapping the units when one is Bluetooth capable while the other is not.

Has anyone else experienced this problem?

I have an email in to Avidyne but doubt they will get to it til Monday.  
Thanks

Steve

[LANCECASPER]

1 hour ago, NotarPilot said:

I want to do some troubleshooting so I want to swap the units to see if the problem follows the unit or stays on the bottom tray. Does anyone know what size Allen wrench is needed to unscrew the unit.

3/32"

https://avidyne.com/files/downloads/600-00316-000.pdf

[NotarPilot]

Thanks Lance. 

[m20kmooney]

6 hours ago, NotarPilot said:

While flying today I began experiencing a new problem with one of my two IFD 440s

There have been comm issues with avidynes. Some think it may be due to old wiring and/or tray that are retained. The fit of the IFD is a little different than the original GNS.

Edited March 16, 2019 by m20kmooney

[thinwing]

Transmit pin shorting to ground

[NotarPilot]

Thanks, I'll have this looked at.