I'm running a Samsung Galaxy S4 Mini.
I'm having intermittent issue with the touch screen freezing and no longer responding to any touches.
The power button works, as does the home key. The volume buttons do not appear to work. Once it's locked I can't unlock.
This appears to happen when I'm trying to use Google Play Music, but not every time. I'm only about 75% sure that the incidence of freezing is tied to the use of Play Music.