Hello All,

my Mavic pro never had any issues so far. Some days ago i tried to start it up and got into Atti mode. My phone was connected and showed the USB messageDJI4 App was running. I did not know what i clicked, but somehow the controller lost connection to the drone. I cannot describe what really happened but the result is:

Start up behaviour:
- i can turn on the drone, get the first 3 tone signal (normal)
- motors are turning for a short moment (normal)
- Gimbal does its auto adjustment (normal)
- short hizzing sound (not normal, or never heard before)

General Status when Drone is on:
- controller cannot connect to the drone anymore
- reconnect controller (binding process) does not work, controller just keeps beeping and cannot find the drone
- I have tried old and new version of DJI Go App
- status light at the tail of the drone is off (nothing)
- DJI Assistant does not find the drone (serial port problem) when connected via USB
- DJI Assistant does find the controller when connected via USB (so i assume not USB cable or DJI Assistan Software problem)
- Cannot find WiFi when Wifi mode is selected on the drone
- I have remove the internal SD card and tried connecting the drone via USB, not successfull

Bottomline:
- because i am not able to connect the drone to my computer / controller / DJI Assitant Software / DJI Go / Dumbldore - i cannot reset anything or change firmware
- No status light indicates a firmware problem (even when startup sequence seems to be normal)
- main issue is the connection issue - if i could connect the drone somehow i could go ahead with troubleshooting but it seems that i am locked out and the only solution would be to send the drone in or replace logic board by myself
- This sudden appearance should not happen - the drone was not damaged or experienced any physical stress - i just plugged in my mobile phone into controller as i did many time

Any help is highly appreciated.
Regards from Germany
Andy

What mode is on the AC?? RC- or WIFI mode? May be the WIFI mode iis switched on on the last card change. But the hizzing sound makes me curious. Did ya get a anormally smell from th eAC ??

Hello,

- Selector is set to RC (not Wifi)
- Hizzing sound is not electrical (short ciruit etc.) - sound like mechanical sound.

Anyhow - main issue is the non connectivity of the drone to USB cable and PC / Remote Control

I will put it on ebay labelles "defect"...

Andy