OK I just had the same problem on two different FC200 egg cameras. One had a black screen with the pinwheel of death and the other was just black. Both had wifi signal, battery, telemetry,both would recognize the SD card, the gimbal worked on both, but neither had FPV. The one with the pinwheel would take pictures, but the one with the black screen could not. When I tried to take a pic or video it would say sensor error. So I suspected it was a different problem with each one. So I opened them both up and inspected the boards. Not surprising I found a fried board in each. The one with the black screen(no pinwheel) was the board attached to the camera/camera lens. Bummer! The one with the pinwheel was the board beneath the board that is hard wired to the fan. Fortunately they were different boards and was able to make one good camera from the two sets of parts. I'm going to call DJI (but not getting my hopes up) and see if they have some extra boards lying around that they could give/sell to me. Fingers crossed! My advise would be to open it up and take a look inside for obvious fried boards (mine were pretty obvious). Other than that I don't think there is a firmware upgrade or downgrade that is going to help this. Sorry to be the bearer of bad news. Happy flying (with or without FPV)!