First year of university engineering course. Electrical engineering practical. Using an oscilloscope to look at waveforms on three phase motor. Follow the instruction sheet, plug motor into mains, connect 'scope to motor. Turn on circuit breaker. Immediately, a sound of, "pzzzzzzzzzzsssssssssshhhhhhhhhhhhht" followed by deathly silence as most of the oscilloscope internals are transmogrified into grey smoke that slowly and gracefully rises to the ceiling.
After a departmental investigation it turns out that the vapourised 'scope was not my fault, as the lab tech who wrote the instructions forgot to include the words"....using an isolating transformer....."
(one of the live connections to the motor was shorted to earth via the input of the 'scope)
Biting the hand that feeds IT
