A 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.
won't affect data on the device.
Press and hold the Power button (located on the right edge) until the Power options screen appears then release.
If the device is unresponsive, press and hold the Power button until it powers off (approximately 10 seconds) then release.