New gremlin and I'm stumped! No trim??

[lancair360]

Had the same failure mode 2 years ago. New AP panel fixed the problem. Old AP panel was reported to have every solder on the main board broken. When problems surfaced again we immediately swapped at the AP panel and the frequency increased from intermittent to constant. During troubleshooting I was able to get the failure to happen even with the AP panel removed from the Dynon network!

Made up a harness for new trim relays to connect to the D15 so I can easily plug back into the AP panel for more troubleshooting or whenever we get a fix. A few hours trouble free since removing the D15 from the AP panel. The AP panel is still installed and online, just not using it for trim relays function and I’ve had no problems.

 

[swatson999]

Had the same failure mode 2 years ago. New AP panel fixed the problem.

Or masked it. It may have addressed the *proximate* cause of the failure, but not the *root* cause.

Who told you all the solder joints were broken? Was that an official documented analysis from Dynon? That seems like it would be really hard to do without seeing lots of faults of various kinds as one after another lead failed.

I'm in agreement here on this being something outside of manufacturing or programming defects. That's a nice way of saying there's something in *your* airplane that is causing it...wiring harness problems, chafing, grounding, horrible RFI, etc. But given all the swaps you've made and it's still there in some configurations (including the original), that would point me elsewhere than the boxes.

The ultimate in troubleshooting would be to remove every device and wire them together on a bench and see if it recurs, but that's unrealistic, I know. Short of that, disconnecting everything that you can and still fly, and then one by one reconnecting them until it recurs *might* point you towards an area of possible root cause.

 

[lancair360]

Dynon found the solder connections when they opened the AP panel. Still waiting for them to get into the AP panel we just swapped out last month to see if there is anything inside it.

Most everything that’s been done is in the last couple pages, that will answer most all your questions about wiring harness and RFI and such.

 

[swatson999]

What about a failure of the network hub? You've changed out most everything else, and seem confident that it's not a wiring problem...

 

[jakej]

Dynon found the solder connections when they opened the AP panel. Still waiting for them to get into the AP panel we just swapped out last month to see if there is anything inside it.

Most everything that’s been done is in the last couple pages, that will answer most all your questions about wiring harness and RFI and such.

Ok, now I believe we‘re close to a solution & that’s the reason for my previous questions.
You have wrung out the wiring, which most do, however there is the forensic side to these issues that should be considered although normally that is not required.
Maybe the ‘fault’ is close to or near to the a/p panel ( no chafing on metal edges etc ?).
I’d suggest replacing the 15pin connector & cut the pins off the wire ends & replace them - simple, easy & a quick job.

I can quote a few examples of & have seen all sorts of quirky things causing a lot of head scratching like a single thin strand of wire cause problems that were not apparent at the get go -you get the drift.
Hopefully it’s resolved soon - it’s taken up too much of your flying time .

 

[lancair360]

The 15 pin harness was rung out and that is all the 12v trim stuff. If something was shorted there it would show up as the trim actually moving, which it doesn’t. The backshell was also opened and each pin inspected. Easy to hear a trim motor firing in the hangar. Also when I had a moment where it wasn’t failed that harness and the D9 cables were wiggled and twisted and a failure couldn’t be induced.

Network hub - Dynon can’t figure how something there would only effect this one system. And s couple plugs into the network hub were moved around and the problem didn’t move. Also when the screens were swapped positions the problem followed the screen.

At this point need to wait for Dynon to open the AP panel I just sent them and check diagnostics off the new HDX screens after the trim wiring was removed from the AP panel. If it still shows a pitch runaway or not and if the AP panel boards are intact or not are all pieces to the puzzles.

 

[swatson999]

I don’t know if they’ve opened up the AP panel I sent back a while ago, if solder joints are again broken that’s a clue.

Yeah...it's a clue that something on your plane is causing them to break. Evidence: No other reports (that we know of, of course) of AP panels where "every solder joint was broken" except your aircraft, at least once. If you see this again on the new AP Panel, it's almost a certainty the fault is in the installation, not the manufacture.

 

[swatson999]

OK, so here's what I see has happened, in the large:

2015 Install (by someone else)
12/20 Failure intermittent
1/21 AP repaired, repairs made unspecified, problem apparently resolved
2/23 Failure “100% of the time””, except not really per post #14
2/23 Report of failure mode 2 years prior: all the solder joints on the main board were broken
3/23 AP replaced; AP Panel offline messages
3/23 AP Panel offline occurs with loss of trim control
3/23 Swapped screens, problem did not move with the screen (always on copilot side)
3/23 New network cables; swapping D9
3/23 Swapped screens, problem moved with screen
3/23 Network configure
3/23 Unplugged D15 and turned off autotrim; Connected “everything”. No failure.
3/23 Pulled “some breakers”, some failures.
3/23 Fails always, varying times to failure; removed “suspect” screen, failures persist
3/23 Replaced both screens with new HDX. No failures
3/23 Next day: same failure mode
4/23 D15 disconnected from AP Panel

In short, you've been shotgunning the problem solving, and getting inconsistent results which lead you down rabbit holes. You swapped screens twice, and once the problem didn't move with the screen, and once it did. So you learned nothing from that activity. Similarly with swapping cables and unplugging things and replacing things...you're changing multiple things essentially at once. You've "broken configuration" so many times it's impossible to follow what failure modes you may have ruled out or in.

I'm trying to be helpful here and not sound pedantic, but you need a *plan*. Start with a *known* configuration....everything, hardware, software, setttings, power available, everything you can think of. Then make a hypothesis, ANY hypothesis: it's this D9 connector. Then think about how to test that hypothesis, and do so. When you're SURE of the result, not just a couple of successful boots and YAY!, then you've got a repeatable configuration that either does or doesn't induce the problem. If you've found it, great. If not, and here's the important part, *put the system back the way it was* before doing anything else.

You're also multiplying entities. TWO AP panels failing in one aircraft, separated by years of manufacturing and sales, with the exact same pattern of failure? That's hardly likely. Or if it IS the case, it's not likely to be the *manufacturer's* failure...something in your plane seems to break AP Panels, if this one turns out to have broken solder joints.

Again, the chances are that this is a problem with *this* particular aircraft's installation, somewhere.

 

[lancair360]

If you scrape this thread for the data you're only seeing a high level overview of troubleshooting and not what's actually been done. Everything has been done in concordance with Dynon and individual components / differential diagnosis on each part, things were only changed one at a time early on in the troubleshooting trying to isolate the failure. Cables seperate from screens seperate from...etc. I'm not going to summarize the 150 plus emails back and forth with them but everything has been done with Dynon by my side throughout the process. They've advised on methods and we have some very specific emails back and forth down to checking indiviual pins for behavior or a specific software setting that can be changed to reveal shorts on a certain board in the screen. Just need to wait on them before next steps right now.

Not possible for the plane to have broken the new AP panel because it was installed and the failures increased, plane wasn't even started or flown. This was all done in the hangar. Every time we've produced consistent results and thought we've correlated the failure to something the failure has changed behavior without any input from us. It just moves or changes timing or goes away for a while.

 

[swatson999]

Well, you seem to know what you're doing, so good luck and report back when you find the cause.

 

[lancair360]

can't wait.

 

[Followthemark]

While we all can feel your pain, some of us don't have either the knowledge or patience to work through the challenges both you and the Dynon support staff have been navigating.
Quick question that I did not see throughout your very detailed troubleshooting steps, have you ever dynamically balanced your prop? One of greatest beneficiaries of a balanced prop is the positive effect on reducing vibration fatigue to the electrical system including chafing, solder joint failures and electrical system components. When you described replacing the AP having solved the problem at least for two years, vibration screamed to me. Clearly this doesn't fix the problems currently, but you might want to try balancing the prop. One important part of the balancing process is in the initial run. A good quality prop balancer will provide exact data as to how far out the prop is from ideal. Once the needed weights are added to adjust the prop balance, like an out of balance car tire, the results can be very dramatic. Good luck!

 

[lancair360]

Balanced to .05 ips