You may got no video on BNF drone like Beta65, Beta65S or Beta75, especially on drone with OSD function. Here is some situations may occur.
1) If there is signal coming through on the channel that the VTX is using, but nothing with a black screen, this is usually caused by disconnection of cables. So can you remove the canopy and inspect the video in and video out cables in the FC. The connector may be loose after crashes.
As show in the first image below, the clip on the JST 1.25 connector is loose. So you could insert it to the connector to fix it.
2) You could connect the video in and out cables togerther to check if the AIO VTX camera is faulty or not. As show below, just connect the video in and out cables with tweezers or wire. If you could get video in your monitor or goggle again, that means the AIO VTX camera could work well.