Dynon Skyview HDX grounding/corrosion point

[rleffler]

Joe is correct. There are many sources of vibrations in a flying aircraft. Any human error in a non perfect crimp, or a wire that isn’t supported adequately, etc will be a candidate to fail at some unexpected time in the future.

It’s not hard to track down, but can be tedious.

Get the Dynon installation manuals. They will document what functions are on what pins. Using a voltmeter, do you have proper voltage on the power pins? Do you have continuity to ground from the ground pins?

When you state the EFIS fails, are you implying the screen is dark from lack of power? Or something else? If that is the case, it could be the power wiring or the ground wiring. The EFIS shouldn’t shutdown at the voltages you indicated. Usually they can continue to run a much lower voltages.

The easiest test is while you have the EFIS powered up on the ground, wiggle the wire bundles to see if that may cause a failure.

Otherwise, you will have to manually verify each connection in the circuit until you find the culprit.

It could something as simple that the pin isn’t inserted all the way into the db connector.

Make sure you take good notes through the troubleshooting. Knowing your systems intimately will help you greatly understand the situation if an emergency should happen in the future. Whomever built you aircraft should have provided a schematic for both power and data circuits. If they didn’t, reverse engineer the wiring and document it. I.e. pin 1 on db connector 1 goes to pin 25 on db connector 2.

[vtails12]

Dynon avionics are and have been very reliable. I have sold and installed their avionics for 5 years and had only one issue and that was a SV-470 ADS-B "IN"
(Dynon's first version) Other than that NO issues reported to me.

As noted previously, the ground and all connections are of most importance for the system to continue to function properly. I once found a loose ground connector on my plane that caused panel flickering and shutdown, corrected this and no problems in 3 years.
If you have not checked all of the connections including both hot and ground connections I would start there.
If you do not have the wiring schematics for the Dynon avionics here are a couple of links to their installation manuals that may be helpful.
Best of luck and I hope the hear the problem was successfully resolved.
Marc

https://www.dynonavionics.com/skyview-documentation.php

https://www.dynonavionics.com/includ...v_AG-v15_4.pdf

[lon@carolon.net]

Originally Posted by rleffler

Using a voltmeter, do you have proper voltage on the power pins? Do you have continuity to ground from the ground pins?

When you state the EFIS fails, are you implying the screen is dark from lack of power?

The easiest test is while you have the EFIS powered up on the ground, wiggle the wire bundles to see if that may cause a failure.

I don't know exactly what the avionics shop did while my plane was there (for 6 weeks). I assume they used a voltmeter to check voltage on the power pins and continuity to the ground from the ground pins. (And, yes, I do remember my flight instructor telling me that the word "assume" should never appear in a sentence about anything having to do with flying.) The avionics shop checked something with a voltmeter, because they concluded my battery had a dead cell, and they replaced it with a new battery, though that didn't help at all.

When the Dynon "failed," the HDX displays did not go dark. They continued to work perfectly. It was the information they displayed that made me say the system "failed." The failures were the altimeter, airspeed, GPS location, and attitude failures that I described in my original post. The data displayed during these failures was confirmed by the Dynon internal "black box" files, by ADS-B Out reports, and by ForeFlight -- all of which showed just what the HDX displays showed.

I have wiggled the wires connected to the HDX displays, but doing that did not trigger any failures.

Thanks Bob. I will follow through with the manual verifications that you and Joe have advised must be done. Because I'm not the builder, and don't even have a hangar in which to work (my plane is tied down outside), I've been looking for another avionics guy near Santa Monica who is able and willing to do the work. I pay my bills promptly. But mechanics and avionics specialists are so busy here in Southern California that I'm struggling to find one that will take on the job or even return my calls.

[lon@carolon.net]

Originally Posted by vtails12

Dynon avionics are and have been very reliable. I have sold and installed their avionics for 5 years and had only one issue and that was a SV-470 ADS-B "IN"
(Dynon's first version) Other than that NO issues reported to me.

As noted previously, the ground and all connections are of most importance for the system to continue to function properly. I once found a loose ground connector on my plane that caused panel flickering and shutdown, corrected this and no problems in 3 years.
If you have not checked all of the connections including both hot and ground connections I would start there.
If you do not have the wiring schematics for the Dynon avionics here are a couple of links to their installation manuals that may be helpful.
Best of luck and I hope the hear the problem was successfully resolved.
Marc

https://www.dynonavionics.com/skyview-documentation.php

https://www.dynonavionics.com/includ...v_AG-v15_4.pdf

Thanks for these links, Marc. I had the Installation Guide, but the schematic diagram is much easier to read than the one I had.

[NinerBikes]

Lon, how far are you from the Pacific Ocean and all the salt air that blows on shore?

[lon@carolon.net]

Originally Posted by NinerBikes

Lon, how far are you from the Pacific Ocean and all the salt air that blows on shore?

Fewer than 2 miles. Yes, tied down in salty ocean air. The two pilots I mentioned in my original post are you and a pilot whose plane is near mine.

[Mich48041]

The first place that I would check is at the ADAHRS. Like Bob Leffler wrote,
make sure the D-Sub pins are seated properly. Unplugging and plugging in a
few times will wear away corrosion. Since the plane is located in a corrosive
atmosphere, some type of chemical spray might help.

[lon@carolon.net]

Originally Posted by Mich48041

The first place that I would check is at the ADAHRS. Like Bob Leffler wrote,
make sure the D-Sub pins are seated properly. Unplugging and plugging in a
few times will wear away corrosion. Since the plane is located in a corrosive
atmosphere, some type of chemical spray might help.

Joe, The ADAHRS is in the plane’s tail, behind the baggage area bulkhead, and VERY hard to get to, so I had a professional mechanic replace it. Also, the ADAHRS has been replaced three times since the problem began, so if there was corrosion back there, I hope the mechanic would have seen it, and by the third replacement I hope the mechanic would have been especially careful to get the pins seated properly. Or are you talking about the D-Sub pins at the cockpit/panel end of the ADAHRS wiring harness?

[Mich48041]

Lon, I was thinking of the ADAHRS end of the cable when I posted above. But
you are correct that the problem could be at the forward end of the cable. Do
not assume that the mechanic carefully inspected the D-Sub connector unless
he was specifically asked to do so.
_I helped a friend troubleshoot his ADAHRS new installation. To rule out the cable,
I made a temporary test cable using CAT 5 Ethernet cable and new D-Sub connectors.
Ethernet cable contains the required 4 twisted pairs. Page 25-2 of the
SkyView HDX System Installation Manual - Revision E shows the pinout.
My friend's ADAHRS worked fine using the test cable.
It turned out that my friend had wired his D-Sub connector incorrectly, pins reversed.

[pilotkms]

Lon, I agree with Carl. Since u are not a builder this has to be overwhelming. An A&P, even an electronics Guy, will have difficulty as u have experienced. Bruce has a 9A with a Dynon panel. He has upgraded other RVs for others. Probably your best bet, and best $$$ spent.