A crash removed my camera and gimbal so I bought some spares and set about the repair On completion, I switched on and, to my surprise, everything appeared to check out. I had greens on the drone and r/c, all parts of the app were reporting and the camera was recording so, with props removed, I moved both controls down - nothing! I then checked everything again and was getting "ready to fly" on the app so I tried again but still nothing. In desperation, I used " automatic take off" and the engines burst into life for a few seconds then shut down again. Since then, all efforts to get the engines to fire up have failed so it's obvious that either I've damaged something during my (amateurish) repair efforts or something else was damaged in the initial crash. Any ideas/help from your droners out there would be appreciated. Mike.