BROM disabled by efuse 0x146: Understanding the MediaTek Security Lockdown

When you power on a MediaTek smartphone, the very first piece of code that runs is not from the main flash storage. It comes from a tiny, read‑only memory built into the silicon itself: the Boot ROM, abbreviated as or BootROM . This initial code initialises the most basic hardware (clocks, memory controller) and then looks for the next piece of software, normally the Preloader , which then loads the main bootloader and finally the Android system.

This is a common hurdle in the device modding and repair community. Manufacturers and carriers often blow this fuse to prevent: Unauthorized Firmware Downgrades:

Ensure you are using the absolute latest version of UnlockTool, SP Flash Tool (v6.x or higher), or MTK Client.