"Looking more about your picture Nr3, like Jay pointed and Chris suspected. I can confirm that they are not original ArduPilot Mega / IMU boards,
Looks like your boards have either bronze or copper based trough holes and pads. Reset button,…"
"Yes i have it soldered on every boards. Don't currently have APM schematics close to me to check it's connection but it I think it was that what connects RC rail +5 to main +5 lines.
It is safe to solder that anyways."
"Yes +5V is on middle pin.
Since i've connected the APM for the first time, I always make many verifications to be sure that no short circuit and no inversion of -/+.
Perhaps some resistor has a problem and "block" the…"
"Ok good because you should have +5v on all of those when your battery/esc is connected. And you made sure that +5v is on middle pin?
Sounds like you have a problem on your APM board, for some reason your RC rail is not connected to main…"
"Those ESCs comes from HobbyKing. The each have proper internal 5v BEC !!
I've just measured 5v on each of the 8 middle/lower pins at APM 3row pinheader. What does this mean ?
So you think that if I plug my 3S lipo on the +/- holes…"
"I had an idea : if a fuse is dead, electricity doesn't pass through : so i've test the fuse and they are OK, so it's not that...
There's 2 fuse. one on each card and they're both OK...
I think the Imu shield is OK because…"
What are those ESCs? Do they have proper internal BEC?
Have your checked that ESC will output 5V from middle pin? You said that you measured 5v from bottom and middle pin on ESC connector but how about when connector is…"
"I don't know if it's damaged because when i plug the usb with mission planner, all works nice ! The gyro, magneto, gps, Rx... all works fine.
So i think there's a problem with the power input... How can i check that ?
And if theres a…"