MP 1,1-5,1 Strange Mac Pro 5,1 oddity. Power over Displayport?

[LongWelsh]

I had a DIMM fail yesterday. Red lights on motherboard, the usual. After unplugging the power I was waiting for the motherboard to power down and the SMC to reset, it didn't, it seemed to stay in standby.

I come back this morning 18h later and the lights are still on with NO POWER connected. So I start unplugging things, the Displayport running to the monitor seemed to be providing enough power to keep motherboard logic running in some fashion at least.

So interesting to know that just pulling the IEC might not be enough.

 

[Macschrauber]

I remember someone telling a warning LED on his Board kept lit due to the connected display.

It's surely not power, but somehow a voltage came in thru the display and gave energy to the LED.