HDMI Get's recognized by Windows but shows Blackscreen

[Lifant]

Hey,
Today I upgraded from a GTX 760 to a GTX 1070
I used two Screens, one connected via DVI and the other via HDMI, everything worked fine with the 760.
Now, with the 1070, I've got a Problem
Windows recognizes the 2nd screen and also that it's connected via HDMI, but the Screen tells me there's "no cable connected" and shows nothing but black.
The screens I use are:
-BenQ GL2250H
-Medion MD20444

What I've tried:
-Switch the Screens, now the Screen, previously connected via HDMI, now with DVI, works and the other one that now is connected via HDMI shows the same Issue.
-Update graphic drivers.

 

[Lifant]

solved, tried another cable and it worked, old cable still works with the old GPU tho...