Hi, if screen turns off, I'm not able to get it back with the power button only with usb-pc. I can not switch the device off at all... I wait until screen turns off but it needs to plugged into the pc to turn it on. By the way, everything works except power button. Tried to longpress, no result... Resetting, firmware updating didn't solved the problem. I thought maybe it is a hardware issue, sort of contact problem... Any idea?