I have a picture then when camera or video button is pushed screen goes black , top reads no video transmission signal then picture comes back,  nothing is recorded
Any one have this problem or any ideas of the problem

Hi, please help clarify your aircraft model, and the firmware version, you could check it on "About" page through APP.
May I know what mobile device you are using? the APP is the latest ?
You noticed this issue after a firmware upgrading or hard landing?