Hello everyone. Could anyone help me troubleshooting? 
I recently had a crash due to a failsafe after RXloss using the DJI FPV RC2 (now looking to buy a Boxer) and replaced the only motor(M2) I thought was damaged.
Within the first flight after replacing it, I heard and saw motors twitching and my O3 video feed with some look like interference lines (images below). -The google's feed was the day after replacing motor and noticing the issues. The log one is two days after, after making a physical inspection and trying to find what was the problem.
DJI support told me to downgrade Googles2 from last version to V01.04.0000 to fix O3 issues, which seems weird and didn't fix the problem.
I also set PIDs to default to see if that was the issue, which is not.
Had checked continuity between positive/negative and motors pads in ESC as suggested on one of Oscar's post. All ok. Checked all solder pads and cables too.
Don't know how else to troubleshoot or what to check as it is my first quad.
All help is appreciated.