issues powering on

if i use a usb cable to power the BBB and connect HDMI it works fine, but that means i cant have an other usb devices connected (mouse, keyboard, ext hdd) using a hub as the usb is taken for power.

when i insert a 5v power supply no lights appear on the board, but below the plug on the board there is some heat as through the plug is doing something.

also, if i plug a usb hub into the usb slot on the BBB then from the hub power it from usb, it works, but doesnt power any other usb devices in that hub?

thanks in advance


So what is the configuration of the power plug on this supply? Is it center hot?