"I had a similar issue with a female Deans connector that came attached to two new batteries. While the physical fit was fine, the electrical contact was not. I believe this caused the twitching that I was getting before I changed the battery…"

"Hi Steven, Thanks for that. Interesting reading indeed! I'm definitely in the wrong thread though, as this is all about  APM v2.5. Yes, It looks more like the second twitch in your video, where one of the 'corners' dips…"

"Hi All, It may not be, but this sounds too much like my quad's issue to keep quiet.Apart from mine being an APM 1.4, and the supplied stock ESCs, the symptoms sound similar:- Random motor(s) don't spin up after power-up. If they do, and I…"

"Mark, Welcome to DIY Drones, You should be used to crashing....   M$   I'm Systems Developer on OS-X and fight with M$ all day long.... I crash my planes more than OS-X"