I am not sure I'd want this at my server room. Every modern device has some sort of power supply -- even 48V devices have "soft-on" switches. Those can, and wil

I am not sure I'd want this at my server room. Every modern device has some sort of power supply -- even 48V devices have "soft-on" switches. Those can, and will fail. A single green LED is essential to indicate this. I can imagine a "smart rack" that would have a proprietary system to detect if a device is plugged in but has a faulty power supply.. but I cannot image this being practical outside of a huge server room with homogeneous devices, like a telephone exchange.