This method tested by me if you have  LG L80 Dual D380 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 and hold Volume Down + Power until LG Logo then leave only Power key again Press Power Key until Factory data reset
  • Erase All user data & restore default settings ? Select "YES" from Volume Down button Press Power to confirm
  • Again Select "YES" from Volume Down button Press Power to confirm
  • Now you can see "Factory Reset Processing..." wait until finished Process
  • After that done device automatically restart
  • Congratulation you are done