New I9100 reboots randomly on miui 3.1.19

Aug 25, 2013
because my phone samsung gt-L5500 stayed stuck and tighten what was the button off and put'''' restart in normal mode and turn and went back to what happened now every time you turn esque sounds and background music miui and then stays black for 1 second and return to miui wallpaper with miui music .. this happens consecutively and nose to do, I need a quick help please! thank you!