I had almost the same thing happening to me when working as helldesk... except it was not a CEO, but an SAP consultant (so probably even more expensive), the laptop wasn't black but the usual off-white Compaq used in the late 90s, and it was the lack of sound.
Since the caller was external, there was a lot of paperwork to sign before I could even go over to look at the machine, with a 3-digit figure being charged to the project team for this... only to discover that the volume wheel at the bottom of the laptop had been turned all the way down.