Open "Device Manager" on your PC. Look for "Android Phone" or "Blackberry Device." If you see "Fastboot Interface" without a yellow exclamation mark, you are ready. Troubleshooting Common Connection Issues
Because most BlackBerry Androids have locked bootloaders, many assume Fastboot is useless. That is false. blackberry fastboot driver
the Power and Volume Down buttons simultaneously for about 30 seconds. Open "Device Manager" on your PC
To connect your BlackBerry in Fastboot mode, you need the official BlackBerry USB Drivers. blackberry fastboot driver