I was out flying one minute I could see the screen then I brought it back and then I couldn’t if I take pictures or videos you can see them on the app but when looking at the screen when taking pictures or video is just blank I don’t know if I Have just pressed something or not is there a reset button I can just reset the whole thing help please.

Hi, we're sorry to know about this situation. I would like to clarify that you're not getting a live feed on your mobile device, however, the photos and videos that you were captured would be saved on the DJI GO 4 app? Have you tried to check if there's a file on the SD card as well? Did you manage to delete and re-install the application to see if there will be changes? I would recommend saving important files and sync your flight records prior to delete the application. You may provide us with a screenshot showing this particular matter. Please keep us posted on the latest progress. Thank you for continued support.

Try doing a reset on the camera settings, its likely that you've switched to a manual mode and are seeing an under exposed image.

With all powered up and aircraft connected to RC:-

on main screen go into camera settings by tapping on 'slide' icon just below shutter icon.

then tap on the 'cogwheel' icon to take you into settings menu.

down at the bottom of this menu tap on 'Reset Camera Settings', that may help you.