Unstable AH/Compass display

[Mriya]

I am currently involved in troubleshooting a Dynon EFIS-D100 installed in a Jabiru J160C. The display was originally replaced due to an intermittant fault (old unit sometimes failing to turn on at all). Once the replacement unit was installed I have had an intermittant problem with the AH/Compass display being unstable. Shortly after successfully completing the NESW cal the display started 'doing loops' with the compass giving corresponding reversal of readings while the aircraft remained static. I turned the system off and then on again and the system remained stable despite further efforts to replicate the defect.
However on the next flight the system became unstable again.
What is the most likely cause of this problem? EFIS fault, Remote compass fault or Firmware issue?

 

[dynonsupport]

What firmware version are you running? Version 5.1 had an issue that can look a lot like this, and it is fixed with 5.1.1.

 

[Mriya]

I have not yet tried to update the firmware and the replacement unit was delivered with much older firmware (V01.08 I think). I am now guessing this should have been upgraded. Is it likely that this will help my problem?

 

[dynonsupport]

Did you get the replacement unit from us? We would never ship a unit with firmware that old. Everything ships from us with the latest firmware. If you really do have firmware that old, it makes me wonder about the unit in general.

I doubt the firmware is your problem though. Only 5.1 had an issue, so any other firmware would be OK.

 

[Mriya]

It was an owner supplied unit. I'll need to make more enquiries as to its history and background. When supplied, the owner stated that he got it from the aircraft manufacturer. Thanks for the info.

 

[dynonsupport]

Oh, and let me make it clear that we will fix it, I'm just wondering how you got the unit because I want to make sure we didn't send you a messed up unit somehow. No matter how it ended up broken or acting weird, we will fix it.

The problem you are having now doesn't sound like a firmware issue, but there is a chance we can send you a file that fixes it. Give us a call or send us a email with our serial number and we can give it a try before you have to mail it in.