My phone screen suddenly went black today. i've had this happen once before and just pressed "volume down" and "power" and it restartet. this does not work this time thogh. it shows the galaxy symbol but then goes right back to a black screen.
also when holding down "volume up" "power" and the home button nothing happens at all. however sometimes when i try to do a screenshot or press the volume buttons it makes sounds or vibrates.