I had a 4-port powered hub attached to my Type 2 Raspberry Pi.
I recently purchased a small compact 7-port powered hub off eBay.
I'm powering the hub with a 5V 2.4A power supply. I'm powering the
Raspberry Pi from one of the powered USB ports. I also connected
the "host" cable from the powered USB hub to the bottom USB port
on the Raspberry Pi. Now for the surprise...
When I unplugged the micro-USB power cable from the Raspberry Pi
to swap it out for a shorter one... my Raspberry Pi stayed on!
I unplugged the powered USB hub from the wall (to power down my
Pi) then plugged it back in. My Raspberry Pi will power itself,
boot, and run from power from the powered USB "host" cable, with
nothing plugged into the micro USB power port.
Is the normal? ... with this damage my Raspberry Pi?
Prof. Michael P. Harris