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 right edge) until the 'slide down to power off' message appears then release.
Drag the window to the bottom of the display to power off the device. Once the 'goodbye' message appears, allow up to 15 seconds for the device to completely power off. If unable to power the device off, remove then re-insert the battery.
Press and hold the Power button to power on the device.