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. In most cases, a soft reset won't affect data on the device, unless the battery is very low.
Perform the alternate reset method if the device is 'frozen' and unable to perform the preferred reset method.
Press and hold the Power button.
Press and hold the Power button for approximately 7 - 10 seconds