[JonJay]

I am posting this to see if there is anybody out there that has had a similar experience that might be able to add something to what appears to be a one time anomaly.

Flight#1
Symptom - slight random static in left speaker of headset that was never there before. 15 minute flight after oil change. No other issues.

Flight#2
Static still there. About five minutes into the flight, momentary static volume increase, Dynon goes gray, two seconds later, black. Static gone. Dynon gone and will not reset when Dynon power is cycled. (Tried multiple times immediatley, then after five minutes.)
Post landing before shut down, cycle master, trun Dynon back on and it comes back to life.
Retrieve data from EMS. One event shows the Amps shot up to 54A but for only one data capture (The EDM 930 reports at 6 second intervals). Voltage spikes at 16v, again for only one data capture. Amperage then reads "0" for a few minutes then 5A for the remainder of the short flight. (Shunt set up as charge/dicharge to meter, not load meter).
Voltage 14.2 (+- .1) throughout all flights except for that one occurance. Amperage normal also.

Checked all wiring, circuit boards, alternator, no signs of chafing, no signs of a burnt connector or wire, everything looks and smells like normal.

Flight #3
Static still there. Cycle Dynon on and off, no change, cycle radio, transponder, strobes, etc... nothing affects this low level static. No other issues and about five minutes into the flight the static goes away.

Subsequent flights - Static gone, about an hour of flight time and no further issues.

I have a couple theories but I will hold them until I hear back.

 

[airguy]

Any evidence that the voltage actually did spike, indicating an alternator/regulator problem? Do you have an independent way of looking at voltage, and did you notice any other symptoms?

 

[JonJay]

No

Any evidence that the voltage actually did spike, indicating an alternator/regulator problem? Do you have an independent way of looking at voltage, and did you notice any other symptoms?

At the time of the event my scan did not show anything out of the green, so the event either was too quick for me to see or my eyes where not on the EMS to see it. No other issues with radio, transponder, or other electrical devices.
Hmmm, here is a question for the Dynon or perhaps 496 experts. Do either of these capture voltage data for reference?

So, one of my theories is that the Dynon had a momentary hic up, threw some junk back on the system, scrammbled the EMS for a bit making a false data point, shut down the pezio circuit protecting the Dynon and would not let it come back on until a complete system reset.

I am on my third Nippo alternator. My experience with the last two regulator failures has very different symptoms. I am not elliminating the possibility however.