Soft reset can resolve issues like continuous resetting/rebooting, device crashing, freezing, won't ring or vibrate, can't make or receive calls, device locks up and keypad doesn't respond.
A soft reset (turning the device off then back on) is similar to restarting a desktop computer and is one of the first steps in troubleshooting a device. A soft reset won't affect data on the device.
Press and hold the Power button (located on the top-right edge with the charging port facing down) until the device powers off (approximately 10 seconds) then release.
Allow several seconds for the reboot process to complete.