> In fact, one of the first test boards the team plugged the ARM into had a broken connection and was not attached to any power at all. It was a big surprise when they found the fault because the CPU had been working the whole time. It had turned on just from electrical leakage coming from the support chips.

So this not an urban legend after all, and it's about the first ever ARM CPU! Very cool story indeed

There's even an interview with Steve Furber, who co-designed it, where he talks about it. https://www.youtube.com/watch?v=1jOJl8gRPyQ&t=508s