Use SP Flash Tool v5.x (specifically v5.1916 or newer) or SP Flash Tool v6.x. Version 5 remains highly recommended for MT6765 due to its stable handling of legacy Android scatter structures.
Modern MT6765 devices implement strict secure-boot mechanisms. The Auth file bypasses or satisfies the chip's internal security checks, preventing "unauthorized flashing" errors. Essential Prerequisites sp flash tool 6765
Before flashing, always backup NVRAM (IMEI data) and NAND Flash using SP Flash Tool’s "Read Back" function. Use SP Flash Tool v5
Extract the SP Flash Tool archive and launch flash_tool.exe as an administrator. sp flash tool 6765