System Event 20 & System Event 21 at startup

MikeD

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May 14, 2023
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59
This is second one I've experienced this year. Master on and all system were initialized. I hit the starter button and the PFD rebooted with System Event 20 and System Event 21 errors. It has also happen to my wingman, whose install is identical to mine. We both have all Dynon Advanced Panels, with 2 10" HDX screens, running 16.7.0. I started tracking time between system reboots this year. MTBF is now 14.15 hours of operation.

At each occurrence I have submitted a support ticket, along with the diagnostic dump file. Crickets.

My understanding is that a Sys Event 20 reboot is caused by a watchdog task that reboots the system when integrity has been lost. I.E. system goes south, reason unknown, can't be fixed, best to reboot. Not sure what a Sys Event 21 implies.

Anyone else experiencing Sys Event 20 and Sys Event 21 reboots?
 
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MikeD

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Joined
May 14, 2023
Messages
59
Do you have DYNON battery backups on displays?

Kurt
Good question. Since both failures occurred during engine start my first thought was voltage sag. However, both displays have batteries, which were recently tested (and passed) during condition inspection. In both instances only the PFD rebooted. MFD remained operational.
 

Rhino

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Jul 20, 2009
Messages
1,480
Dynon was looking into an issue with sys event 20, so you may want to contact them.


Others have gotten sys event messages with loose conectors, so you may want to check those as well.
 

HEB1022

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Mar 21, 2023
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I had a SysEvent 20 and reported to Dynon along with Diagnostics file. No resolution.
 

RV9APlane

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May 3, 2009
Messages
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Location
Bakersfield, CA
Yes, have had a SysEvent 20. The PFD rebooted itself several times at startup and then the MFD did the same thing. I exported a diagnostic file but havent submitted it yet, I was on here looking for how to do that and saw this thread. I have the Classic system and had just replaced the backup battery for the PFD and this was my first startup after having done that.
 

jsalak

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Apr 29, 2013
Messages
36
Location
FL
I was plagued by System 3, System 5, and System 20 reboots for 5 months last year. They started right after I updated to 16.5.2, typical event was pulling back power on decent and the system would reboot. The reboots would usually continue to landing once they started. Sent the SV-D1000 back to Dynon twice and even got an exchange unit with no change in the reboot occurrences. Updating to 16.6.0 caused the reboots to start within a minute or two of starting the engine. Took a few months, but Dynon ran the problem down and I tested the fix with a 16.7.0 beta release and no more reboots since that point. I checked every bit of wiring, backup battery, WiFi, USBs to no avail, even a test flight with the IFD540 turned off. The good news is at least I have no problem flying and landing the plane with a blank EFIS on final.
 

JohnBanes

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Aug 7, 2013
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Same issue with Events 20 & 21this morning. Exporting Diagnostic File has been stopped at 43% for >30 minutes. It says “Do not power off during export” What should I do?
 

JohnBanes

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Aug 7, 2013
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Same issue with Events 20 & 21this morning. Exporting Diagnostic File has been stopped at 43% for >30 minutes. It says “Do not power off during export” What should I do?
It just stopped saying it could not write to file. Total time about 40 minutes.
 

MikeD

Member
Joined
May 14, 2023
Messages
59
It just stopped saying it could not write to file. Total time about 40 minutes.
Sounds like your system was too unstable to complete the export. If it doesn't complete the export in 5-10 minutes, I would reboot and assume that the diagnostic information was compromised.
 

MikeD

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Joined
May 14, 2023
Messages
59
Some encouraging news from Dynon Tech Support. I received the following update yesterday....

"We do have engineering working for the System event 20 and 21 bug. They are supposed to have a fix out in version 17.1, which should be out sometime around Oshkosh."

Fingers crossed.
 
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