I have been investigating the issue of black screens and I have a good idea what is wrong.
At the lower driver layers WDDM is the what interfaces with the kernel etc. If something is not right, you can see a timeout error which will cause the screen to momentarily go black.
This is a problem is part with AMD and in part with MSFT. WDDM manuals are complex and I noticed they still do not have all I would want.
DXGI is on top of WDDM and the communications up and down is where the problem lies.
I can reproduce this with a new wiped disk and a Radeon video card. Curiously my HD 7870 does not exhibit the problem which suggests a video card BIOS may have some effect I have not yet been able to detect.