You have a Caddx turtle V1/V2 and you can see only a yellow screen like this one:
54190751_10218733708076170_2986358655751815168_n-1

The main reason is probably the cable between the camera and the board, it could be like:
55575595_10156917727420309_6516576057984811008_n

So if any of this cable is damaged you can replace them by getting new one from caddx directly:
55_2000x
V1: https://caddxfpv.com/collections/cables/products/caddx-turtle-coaxial-cable
V2: https://caddxfpv.com/collections/cables/products/turtle-v2-coaxial-cable-5cm-and-10cm

It is also possible that your cable is ok so in this case it is probably more a problem in the board :( So here some links to get some: