Your firmware package may be a single .pac file (Spreadtrum) or a folder with a scatter file (MediaTek).

File name example: SP_Flash_Tool_v5.2208_Win10_upd.zip – the “upd” indicates compatibility with Windows 10’s USB stack.

Windows 10 (especially versions 1709+) requires signed drivers.
MediaTek’s usb2ser.sys (for Preloader/BROM mode) and Qualcomm’s QDLoader driver (for EDL mode) are often unsigned or use old test certificates.

Solution:

  • Or use bcdedit /set testsigning on (then reboot)

    • Cause: Battery voltage too low or dead battery. Fix: Charge the phone for 2 hours using a wall charger. Then try again.

    You need to be in the Bootloader/Fastboot mode to flash firmware.

    Method A (From Android):

    Method B (Button Combo):

    BQ, the now-defunct Spanish tech company (acquired by Vingroup in 2019), produced a range of Android smartphones, tablets, and e-readers. Even though BQ no longer manufactures new devices, many existing users still rely on firmware updates to fix bugs, unbrick devices, or upgrade Android versions. The BQ Firmware Flash Tool is the official PC software designed to flash stock firmware (usually .mbn or update.zip files) onto BQ devices via a Windows computer.

    This review focuses specifically on using the tool with Windows 10 (64-bit, version 20H2 and later), covering installation, usability, performance, and common pitfalls.