T-mobile LG G Stylo H631 users who have bricked their devices may follow our step-by-step guide below to unbrick the device and restore stock Firmware using LG’s new LG UP flash Tool.It is very easy to use LG UP to unbrick/restore your phone bakc to stock. LG UP supports KDZ/TOT/DZ firmware from LG.
Some LG H631 Model has Qfuse (Anti-rollback), So you can not downgrade the OS of your Phone,.
What you need to unbrick LG G Stylo H631:
To Unbrick or Restore your phone, Download the LG UP TOOL, LG USB Drivers, H631 DLL for LG UP, and H631 firmware from above links., and then follow this guide to flash firmware onto your LG H631.
If the LG UP can not find your phone, please put your into download mode first and then run the LG UP software.
You need to re-install the LGH631_DLL.msi if you experience above issue. On your PC, Right CLick LGH631_DLL.msi, Click “Uninstall” first and then re-install the file.
Boot your phone into download mode and then connect your phone to PC via USB cable and Let your PC install all needed USB drivers.