Saw in one EE thread that this yellow port is a sort of port that can still
provide electricity when the laptop is shut down or sleep mode?
In my case when my X220 is shut down or in sleep mode, if I plug in my
Android phone (or any other devices that are charged via USB) to charge
from this yellow port, it doesn't charge.
what's the actual purpose/function of this yellow USB port?
is there something I must enable or configure (in BIOS or I have to use
IBM Lenovo Thinkvantage to enable this "pass thru" charging?