The phone turns on but never loads the home screen. It continuously restarts or freezes on the "Jazz Digit" logo. This is often caused by corrupted system files.
This document provides the essential information for flashing the Jazz Digit 4G Lite device powered by a Spreadtrum (now Unisoc) processor. jazz digit 4g lite flash file spd
You performed a "Download Only" mode without formatting user data. Re-flash using "Format & Download" or after flashing, perform a factory reset from recovery mode. The phone turns on but never loads the home screen