I got the same issues, and it's such a pain in the a**. My whole final work is in the SP2, and I could not get it out. I've tried 2 buttons shut down and nothing happened - the device just "black off" and still vibrates when I touch the Window logo. And
it's such a huge surprise to me when I left it unplugged for 3 weeks and today it
still vibrates. Don't know that its battery could last so long.
I've called MS for support service, another huge pain because I'm not in the U.S so I have to wait until June 2015 to send it to the U.S with a friend of mine (there's no MS shop in my country, s***). Now it look like a fancy black picture frame, too big
to be a good paperweight.
By the way, is there anyone around have screen issues? Mine sometimes self-touches (I don't touch it, the device touches itself, sounds weirld). And sometimes the screen does not respond at all. Re-install the device to factory condition did not help.
I used to think that I would live with the screen issues, because sending it to MS in America is so hard but the device would not start, so I got no other choices.
I paid more than $800 for this SP2 months ago, and I expected more than this. By the way, my official salary is $300 (middle-level) so it's high-end product here. D***.
Sorry for the long post. If anyone got any ideas that helps, plz tell me.