Gregory's Server@laird I bet it was the KVM cables. There's no way for Ethernet to power anything other than via PoE (which needs explicit hardware on the receiving end), but HDMI/VGA cables have a convenient 5 volt pin. It's supposed to be from the machine to the monitor, but I wouldn't at all be surprised if some random KVMs get that backwards and backfeed power into the hosts...
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@marcan ah, L440GX+, not BX+. That was the one where the AGP bus was bridged into an extra 64-bit PCI bus.  @laird That... that must really have been out of spec. If it was not PoE I have no idea how you managed to power a BMC though a transformer-coupled Ethernet link! |
@marcan that's pretty much what I'd expected at the time, but the problem followed the Ethernet cable. I could repro with nothing else plugged in.
This was (iirc) an Intel L440BX+ motherboard and an early Cisco 4006 switch. I'm pretty confident that whatever was happening, it was *way* out of spec.
Intel's first couple server boards (the T440BX and L440BX+) were *weird*. Like, the T440BX powered the CPU from the PSU's 3.3V line, drawing 2x the amps most early ATX PSUs provided.