: USB 2.0 ports are highly recommended; USB 3.0 ports frequently cause connection errors (e.g., S_COM_PORT_OPEN_FAIL ) during the flashing process.
| Problem | Solution | |---------|----------| | “BROM ERROR: S_BROM_CMD_STARTCMD_FAIL” | Install MTK USB driver properly, use USB 2.0 port | | “SP Flash Tool not detecting device” | Try Volume Up or Down while connecting, or battery disconnected (if removable) | | “Driver signature error” | Reboot into Disable Driver Signature Enforcement mode | | “Error 0xc000007b” | Install VC++ redistributables (2015–2022) | | Device shows as “Unknown USB Device” | Use to force install WinUSB or libusb driver | bq firmware flash tool windows 10
The user selects a scatter file (for MTK) or a programmer file (for Qualcomm) from the device’s specific stock ROM folder. : USB 2
