Same problem since several month on my NP1
The phone randomly triggers the power button. Sometimes just short press (screen on/off), sometimes long enough to bring up the power-menu (hold-press), and sometimes permanently so the phone will boot over and over again.
As it isn’t reproducable at will, I don’t have high hope to send it in, as the quick check at service center will probably result in “sorry but we couldn’t find anything, here you have your phone back” and that feels like a bit much hazzle to be honest.
Did anyone already pass this procedure?