My Phantom 2 H3-3D with mini-iOSD in Naza mode has developed a worrying habit, which yesterday resulted in a crash. Since Sunday, on three separate occasions, at three separate locations the Phantom has started up and flown fine. Full GPS lock (10 sats) , flashing green legs, normal operation etc. Then I start to get control problems and on the FPV screen the sats go down to zero! It's too far away to see and colours on the LEDs. I try ATTI Mode, no change to controllability (but the FPV screen does register the mode change), then Return to Home, again no response, but FPV screen does show RTH. Still with 0 sats. Fortunately I was high enough to try these things. Then as a last resort, as my Phantom was disappearing into the distance, I turned off the controller. Hey-presto, 10 sats come up on the screen, and the Phantom starts to come home. However, When roughly overhead, it starts to toilet bowl around before settling down and descending. With just 10 meters to go I decide to turn the controller back on with the switches back to normal. All the leg LEDs show solid red, 10 sats disappear to 0 and control is difficult. With the Phantom rapidly sinking and veering towards a hedge I shut down the controller again. Then for a brief period the Phantom started to rise to the default 20m return height, but it started to toilet bowl again before cranking over and blasting off at a 60° angle, scribing a graceful if short arc into the depths of a corn field. Fortunately, only little damage occurred, the H3-3D and GoPro detached from the base (braking the safety tethers), and I have it all recorded for further analysis. So in summary:- Flights start normally Then Sats drop to 0 and the Phantom is uncontrollable Phantom is still receiving signals from the controller as mode changes are displayed on the FPV screen Turning off the controller gets 10 sats back and begins the Return to Home Some issues with the return when over the home position Turning on the controller shows red LEDs and 0 sats and little control Turn back off and some normality returns, but it then arrows off to crash Now I did fit a new H3-3D on Saturday, so suspicion must point at that being the problem although it works fine itself. Could the anti-interference board be connected the wrong way round? Could this cause the problems I've described? I do get a high pitched noise on my GoPro footage..... Would love to hear your thoughts and whether the Naza or mini-iOSD logs the flight so I can analyse things further.