Computer C is a Mac!
I was showing a manufacturing engineer the problem and the video ram of the pc diagonally across from mine was affected. (now only if my personality...)
I guess the best story was the manager whose office adjoined
the ladies room. You'd hear a profanity when somebody started grabbing paper towels.
Grounding did not help. Chassis, table, electrical.
I started getting reimbursed for the cans of "Cling" or whatever the anti-static spray was at the time.