Apm pro mini minim osd problem

Hey
I have s Problem with my minim OSD and my apm pro mini.
Ive connected soldered the pins fot the 5v power on the minim osd . I also power the cam and vtx direct from the current sensor .
But i obly got a blsck screen on my vtx.
Whats wrong?
Can someone tell me how to setup minim osd with the apm pro mini?
Cheers