Actually this is exactly what happened to my phantom after replacing the camera.
I've contacted DJI support and they said it may to update the firmware. But I'mnot able to update it because the aircraft doesn't connect to DJI app.
They also said that I may installed the camera incorrectly and I need to send it to the local center.
I'll try to recheck the cables again..
I really don't know what to do... and I don't know why replacing the camera causes this issue...
I started to get bored of this phantom... after paying almost 1000 $ ( phantom + camera) I can't fly it and I don't know why!!!