Although my 750 flies very well (I have 50+ hours on it), I continue to
           have problems with my MGL panel. I have talked to both Matt at MGL and Wayne
at composite designs (LSA power panel) multiple times without success
in solving the problem. The bottom line is that my MGL radio (V6) and
Discovery lite EFIS  work fine while my engine (Jabiru 3300) is off. Once I start the
engine, the AHRS part of the EFIS quickly freezes, and my radio stops
working. The intercom works, the numbers stay on the face, but I don't
receive or transit. Sometimes, keying the mike ( PTT button) will start it
working, but at best it's intermittent. If I recycle the EFIS power, the
EFIS will work for a while, then freezes again. Just the AHRS part. The
engine monitoring stuff from the RDAC has always worked fine. I traded out
the EFIS once to no avail. I put a capacitor across the power supply (as
suggested by both Matt and Wayne) to no avail. My first flight was 6 January 
            and other than my test area, I haven't ventured very far without a
           reliable radio and EFIS (I have steam gauge ASI, altimeter, skid ball and compass
as well as a garmin 496 so I've never been or felt unsafe). Even though I
            have about 8k in the MGL system (EFIS, radio, transponder and ADS-B), after 10
months, I'm about ready to throw in the towel and put in another system.
I've had an avionics guy working on it for several months now, redoing
grounds, checking coax and shielded wires, etc.  He is as befuddled as me.
           I can't help but think the Jabiru has something to do with this, and perhaps
specifically the voltage regulator (which I got a new one and changed as
well). My voltage regulator is wired as prescribed by Wayne for the Jab 3300. Anyone have any thoughts or ideas on this?  Thanks.

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 Since a time interval is required for event to occur - a situation of power drain reducing the power below minimums for the electronic requirements?

Well, after trying everything suggested (redid grounds, inline filters, transorbs, etc., etc.,) I asked Matt from MGL if I could upgrade from the Discovery Lite (7" screen) to the Explorer Lite (8.5" screen).  On the rare occasions that the Discovery lite actually worked, I was finding it a bit small for my 65 year old eyes anyway and I was hoping a completely different unit might make a difference.  I had tried everything else.  The connections to the Discovery lite and Explorer lite are identical, so all it involved was removing and returning the Discovery lite EFIS for a small upgrade charge ($215), cutting a slightly larger opening in my panel, and when the Explorer Lite arrived, plugging it in and firing it up.  The Explorer lite has worked perfectly from the start!  Matt had programmed it the same as my Discovery Lite, so engine information, fuel tanks, fuel flow, etc. all worked and were the same as before. I also finally have a fuel counter on the panel!  Not only did the AHRS stuff (artificial horizon, airspeed, altimeter, climb and descent rate, etc.) work consistently and accurately, so did the transponder (finally!) including the mode C aspect.  I'll have to figure out how to check that the ADS-B out is also working.  Needless to say, after a year and a half struggling to get a working system, I'm finally there and am extremely pleased with the results.  I can only surmise that both of the Discovery Lite units that were sent to me had a common flaw that was intrinsic to the unit itself.  Anyway, thanks to Matt for continuing to be helpful throughout the entire process.  I'll start looking at the calendar and see if there's a way to make the pilgrimage to Mexico, MO this September!  Thanks for all your suggestions.

Steve Hetz



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