For version 5240400000, the legitimate SHA-256 (once confirmed by community) should match a pinned post on XDA.
Click the large green button at the top of the interface. The tool will enter a standby state, waiting for the device to connect. download spflash tool version 5240400000 new
: Improved handling of connection errors and general bug fixes to prevent "BROM" errors during the flashing process. How to Download For version 5240400000