5 Common Squawks On The Avidyne EX Series MFD

August 2023

We have been servicing Avidyne Corporation EX-500 and EX-600 MFDs (multi-function displays) for nearly 10 years at the Duncan Aviation Component Repair Shop in Lincoln, NE. We’ve learned a lot and want to share the five most common squawk items.

1. Encoders- The knobs (encoders) on the front of the unit are one of the highest failure items on the Avidyne units. The squawk typically appears when the function screens will not advance to the next page or will skip pages. When this happens, replacement of the encoders is the only option to take care of the squawk.
2. Batteries - The Avidyne EX500 units are equipped with 10-year batteries. As the battery begins to fail, the unit clock becomes inaccurate and stops syncing with the universal GPS clock. When this happens, your XM weather may become unusable, and the only fix is to replace the battery. 
3. XM Client Terminated – When a large number of AIRMETs are sent from the weather provider, the EX500 may encounter an overrun, which causes the XM Weather processor software to shut down. This will then cause a ‘XM Client Terminated’ message to be displayed, which indicates that the EX500 is no longer processing XM Weather data. The current software release (4.1) addresses this issue, and prevents large numbers of AIRMETs from stopping XM weather data processing. You can verify the version of software installed on your EX500 by the software P/N displayed on the AUX page. Release 4.1 is software P/N: 530-00201-800. 
4. Memory Card - The charts and navigation databases have gotten so large that the initial memory cards installed on these units are not big enough to hold all of this data, if there are multiple failed segments on the memory card. We replace a lot of the flash drives. The replacement flash drives now being installed are 2GB, compared to original 512MB memory cards. 
5. Intermittent Software Failures - These software failures can be described as anything from a particular function not being accessible to the unit being stuck on the logo screen during boot-up. The squawk is taken care of by removing and reloading the most current version of the software. To prevent these software failures, the EX500 should be shut down before you reach for the Avionics Master Switch. Hold the POWER button on the upper right-hand corner of the unit for 3-5 seconds. The unit will power down on its own.

If you begin to experience any of these squawks, it is time to send in your Avidyne EX500 Series MFD for service and repair.

Duncan Aviation also services Avidyne Flightmax, ATD-150, and MHD-300.