Q: Does anyone know when the first DNF occurred due to an electronic failure rather than a mechanical one or a shunt? They had electronics in F1 that far back?
A: Wrong this time, Julian. It was Juan Manuel Fangio in the Alfa Romeo 158, at the fourth ever world championship race, the 1950 Swiss GP. He retired from second place on lap 33 and his teammates Farina and Fagioli went on to score a 1-2 finish. With the six points Fangio lost that day he would have won the world title that year. EDIT "Electrical failure" could be a wire coming loose, the wiring loom catching fire or a cable snapping, so they did have those problems that far back! If you mean something like a "modern" ELECTRONICS problem, then I think they got primitive computers in around the mid-80s...I remember Senna went through a phase of electronics problems at Lotus...not enough to cause him to retire, but enough to slow him down. Senna only once retired with "electronics" (as opposed to electrical) failure, the 1989 US GP. Patrese had a couple of electronics retirements in 1987, Mansell once at the 1991 Belgian GP. Lauda had one each in 1984 and 1985, and his retirement at Detroit in 1984 is the first one I have found attributed to "electronics failure" rather than an electrical problem.