It’s the late ’70s and pilot fish is a student operator in a small college’s computer room, where there’s a midrange system that’s a bit balky and temperamental. The vendor is called in from time to time, but of course, the machine works flawlessly anytime vendor support shows up.
Between those visits, the machine continues to go down, but fish and his colleagues discover that they can anticipate a looming shutdown by watching the lights on the machine, and a good thump applied in the right place at the right time would keep the thing running.
This goes on for years. In fact, it is only when the system is being removed that it’s discovered that it has a loose screw, and those therapeutic thumps somehow managed to put it back where it needed to be.