I have a Gigaset QV830, the touch screen became unresponsive recently...
But it seems that if I want to turn it completely off, I have to press power off on the screen. I wanted to hard reset it, but can't since it won't power down.
I tried to press volume up & power at the same time... It just restarts itself.
I'm attempting to usb debug it as well, but of course that's not enabled, so I'm at a lost of what to do about this.