Hi, rlagrange,
It appears to me that your problem can be described as the image being sent by the Intel driver to the wrong screen. Your preferred screen, connected via HDMI, is dark, but a second screen, the one connected via VGA, displays correctly. (In my case, my preferred screen, connected via DVI, stays dark during a CHKDSK of the system drive, but the HD TV connected via HDMI displays the CHKDSK output.)
It appears that the problem that most of us are contending with is that the Intel drivers sometimes send the image to the wrong display. Our primary display indeed goes dark, but the image is being sent somewhere else. If that's the problem, it will enable Intel to determine the cause and develop a fix.
Thanks and regards, Andy_A