In 2014 there were many posts about no audio on HDMI output on VAIO Pro. The most promising path to resolution of this problem was a new or updated graphics driver for VAIO Pro. Hope for resolution was promised in a post referencing a download named EP0000317186.exe from dlv.update.sony.net/pub/vaio/dwnload. This was purported to provide an update to Intel graphics driver version 15.33.5.64.3316. But this package actually, when unpacked and installed, contained driver version 10.18.10.3316, and (at least on my Pro 13 Ultrabook) did not resolve the problem on Windows 8.
So my first question now is "Where can I get a graphics driver update for VAIO Pro Ultrabook that will resolve this problem, and what are the restrictoins or requirements, if any, with respect to Windows Version (8, 8.1, 10) with which this update will work?"
My second question is "Is anyone listening? Is support for VAIO Pro now dead because the product is discontinued?"