With the latest device that bit the dust, the PoE symbol was there on the switch port, but no link light, and if my memory serves me correctly, minimal power consumption was metred. In this case, we don't yet know if it is a typical diode failure that was the issue with other devices from the same vendor, or something else. The third party device itself appeared to be completely dead. No lights, etc. Could it be that other devices (or sub-standard cabling with other devices) might be causing issues? Such as a short? I've seen PoE switches being reverse-powered by PoE supply from another switch, despite that not being a documented capability that we could find. Pretty freaky but perhaps handy at times. I've seen these switches also not "take on" AC supplied-power (which would be DC anyway), and when in that state would have to be disconnected form their PoE surrogate to be "righted". I think this was a SG300-10. But in my mind, this behaviour is a sign of how "simplistic" these switches could be. I would expect switches like Meraki to be a lot more regulated.
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