This method tested by me if you have LYF LS-5002 device in that issues of like hang on logo, restarting problem, pattern lock, screen lock then you can use this guide and this without any box you can do just before use remember of must be charged your device battery cause if low device turns off during the process not starting so carefully use.
Before use save your data which is in device cause some impotent like contacts, messages, emails, photos, videos, calendar, notes etc if in SD Card so no need to backup but I suggest first remove SIM Card, or SD Card in device after following this guide or need hardware related that to be working well  which is device volume up, down or power keys for that solve need keys. Must be charged a battery up to 75% now let's go how to solve above issues using this guide ?

Procedure

  • Press & hold Volume Up + Power until Android System Recovery Menu
  • Select "Wipe Data / Factory Reset" from Volume Down button Press Power key to confirm
  • Select "Yes -- delete all user data" option using Volume Down key Press Power key to confirm
  • You will see Wipe data processing like below
    • -- Wiping data...
    • Formatting /data...
    • Formatting /cache...
    • Data wipe complete.
  • Last select "Reboot System Now" wait for device start normal a few minute
  • Congratulation you are done