Mavic Mini no signs of life

Droning on and on... · Jun 4, 2020

Hello
I have Mavic Mini which out of nowhere stopped giving signs of life. It charges the battery and lights up when connected via USB but does not respond to button press when only the battery is connected. I started troubleshooting it by disconnecting IMU, camera, gimbal, GPS and so on. I'm not sure but it looks like ESC/power board issue to me. Does anyone have schematics or information on power rails in Mini?

Thanks in advance

Davros007 · Jun 4, 2020

Have you tried another battery?

Droning on and on... · Jun 4, 2020

Actually don't have one. Tried using a bench power supply - same thing.

Deleted member 103366 · Jun 4, 2020

Re "Tried using a bench power supply - same thing." is it? That's a genuine question. I count 6 terminals on the battery, presumably they are not all plain +ve & -ve.
I recollect problems with a Phantom 3 if it couldn't 'talk' to the battery via some of the 'spare contacts'

Droning on and on... · Jun 5, 2020

Mavic Air and Spark are able to work via power supply when voltage and ground are connected. Some things might not work correctly but it should at least boot. I can't see any reason why it would be different on Mini.

Deleted member 103366 · Jun 5, 2020

Fair enough, it's your drone to experiment with, good luck.

scro · Jun 5, 2020

Have you checked the power button is actually making contact internally when you press it? I've had buttons like this fail due to ingress of dirt between the contact faces of the switch.

Droning on and on... · Jun 5, 2020

Yes, it's making good contact. Pressing it when connected via USB makes LEDs light up.

I need some clues what is power rail design on Mini and possibly a pinout for ESC <-> Core Board connection. I suspect ESC might have became broken but might be an easy fix.

Don't worry guys. I have some limited background in board level repairs. I also fixed a few drones before. I have just never worked on a Mini before. It's new to me and so much stuff has changed with it.

Droning on and on... · Jun 19, 2020

If anyone is looking for solution:

My Mini appeared to be completely dead. No signs of life when powered by battery. It was lighting up when connected via USB tho. I finally found the issue. I knocked off one diode near power button when removing glue from gimbal/camera connector. There are two fast switching diodes. I replaced it with different one (it doesn't really matter as long as it's fast enough) and it's back from the dead! The glue they used is just terrible, very difficult to remove.

I had another issue with the drone so I might share the solution too. It wasn't reporting battery S/N and level. On the battery connector there are 2 data pins (SDA and SDL) as well as ground and 8V. Both data pins should be 3.3V. One of the pins was 1V on my ESC. These data lines are protected from ESD via a small diode connected to ground. One diode had minimal short to the ground so it was lowering the voltage to 1V. You can remove the diode as it isn't required. The diode is most likely ESDA8V2-1MX2 (https://www.st.com/resource/en/datasheet/esda8v2-1mx2.pdf).