A soft reset can resolve issues like continuous resetting/rebooting, device crashing, freezing, 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.
Press and hold the Power button (upper-right edge).
Tap Power off.
Simultaneously press and hold the Volume Down button (left edge) and the Power button (right-side) until the device powers off (approximately 5 seconds) then release.
Allow several seconds for the reboot process to complete.