I saw a brief movie clip (in color) of a man bound to a chair or table (vague recollection) being slowly drilled in the head by a fairly large bore drill bit. I do know that I saw this in the early 80’s (before 1984) and it was on video, so it had to be from the very early 80's, 70's or quite possibly the 60's, and was possibly a coming attraction or preview. Thought it had something to do with faces of death but clearly was not in that movie. I am very sure of when I saw this.
"The Gates of Hell" (Italy; 1980)?
Also known as City of the Living Dead, this was an Italian gore film directed by Lucio Fulci. This was one of the most notorious gore scenes of the '80s VHS boom. It is prominantly featured in the old VHS trailer from YouTube, which I posted below.