Bq | Firmware Flash Tool Windows 10
SP Flash Tool: The Windows software that writes the firmware to the phone.
MTK VCOM Drivers: Windows 10 requires specific drivers to recognize the phone when it is switched off.
A Good USB Cable: Preferably the original one.
For phones like the BQ Aquaris U or BQ Mobile BQS-5070.
Click “Options” > “USB Speed” > Set to “High Speed” (not Full Speed).
Power off your BQ device completely (remove battery if possible, or wait 30 seconds after shut down).
Click the big green “Download” button in SP Flash Tool.
Now connect the powered-off BQ phone to the Windows 10 PC via USB.
SP Flash Tool should immediately detect the device (a red bar will appear, then purple, then yellow). This means the Preloader / BROM mode is working.
Wait for the yellow bar to complete. Once a green checkmark appears, you’re done.
Disconnect and boot the device.
| 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 Zadig to force install WinUSB or libusb driver | bq firmware flash tool windows 10
