The preloader is the first-stage bootloader on MediaTek chipsets. It initializes hardware (RAM, clocks, storage) and loads the secondary bootloader (LK – Little Kernel). It resides in a protected partition (usually preloader), and if corrupted, the device won’t boot or even show a charging logo — often called a dead boot or hard brick.
If preloader is not completely destroyed, you can enter BROM mode (BootROM) which cannot be killed by bad preloader. mtk preloader repair tool fixed