X thinks it is up, but screen is black?

[Temlakos]

On 07/05/2014 12:59 PM, Tom Horsley wrote:
> In my quest for more pixels, I'm trying to get my
> new UHD monitor working in 3840x2160 resolution.
>
> The nouveau driver doesn't know how to drive
> the GTX 750Ti card, so I had to install the
> nvidia binary drivers from rpmfusion.
>
> At this point, everything seems to work except
> for the one minor detail that the screen is
> always black :-).
>
> X thinks it is up and running, the Xorg log
> file shows it recognizing the video card
> and selecting 3840x2160 resolution. Nothing
> that seems like an error appears anywhere
> I've looked. I just have that black screen
> problem (Ctrl-Alt-F2 does get me to a console,
> so it works fine in console mode - it also
> worked in 1920x1080 mode on a different
> video source that couldn't support UHD
> resolution).
>
> Does any of this sound familiar to anyone?
>
> (I'm off to try stuff like a different cable
> in the hope that it is something dumb).

It sounds a little like the black windows/pop-ups/dialog boxes I kept 
getting ever since I took an upgrade during the F17 cycle. But when I 
installed F20 on a new machine and migrated to it, I did not get that 
problem.

Temlakos