something very strange happened today.
Tested the quad on a table no issue at all.
Once ready for maiden, just after take off pixhawk get stuck with “something like” minimum spinning prop and no other reaction. Telemetry drops and not able to do something with remote. I wait up to 3 minutes in that condition (drone on the grass, motor spinning at minimum) that I detach the battery and, after removing propellers, restart it.
I replicated the problem 4 times. It happen when vibration become higher (acc bug?)
At the moment I loaded a previous version and that the 3.6.4 and the issue disappear.
Atached you can find the log of the "flight"2019-01-15 14-31-13.log (207.4 KB)
A quick look at your logs indicates a very bad vibration event when you try to spin up the motors.
I would address that before anything else.
You have 2 GPS’s. How are you powering them?
Radio?
Are you powering every thing from the Cube?
As the issue does seem to relate to vibration I would unplug everything from the Cube to get it back to basics.
Test it in minimum configuration and check all the pins of all the connectors as you put each back in and test one at a time.
I would recommend you have seperate power supply for your peripherals instead of trying to power them all through the Cube.
Could you strip any external sensors off and see if you can repliacate,
please? Just trying to narrow things down. If it happens purely on
internal Cube sensors it should be easy for a dev to replicate.