Try powering down and unplugging everything, then waiting a bit for all power to dissipate (at least half an hour) and then see if the machine will allow a connection and initialize then.
On Microsoft DOS we called it the 3 finger salute. Control Alt Delete to reboot. Now in Windows it does something else. How many times in my life have I given the 3 finger salute to Microsoft when I should have only been giving Microsoft a 1 finger solute.