What to do if your flight controller can't connect to the Betaflight configurator or can't flash firmware?

Before everything, make sure the Betaflight configurator is up to date and compatible with your flight controller. 

1. Please try connecting the USB cable to other USB ports on your computer, or try using a different USB cable.

2. Try restarting the Betaflight configurator and your computer.

3. If your flight controller keep getting the error "Failed to open USB device!" as shown below:

Or, your flight controller can't enter DFU mode even if you press and hold the BOOT button when powering on the flight controller.

Or, your flight controller can be recognized but when you try to connect you get the error above.

Perhaps this is caused by improper driver installation on your computer.

You may follow these steps to troubleshoot:

1. Download ImpulseRC Driver Fixer. It's an executable program and can only run on Windows PC.

2. Connect the flight controller to your computer and launch the Betaflight configurator.

3. Then double-click to launch the driver fixer. This tool will detect the flight controller and install the DFU driver automatically.

4. Continue to update the firmware for your flight controller in the Betaflight configurator. Done.

If nothing helps, you may have to install the drivers one by one by yourself on the Betaflight configurator's Welcome page :

You could install these drivers one by one and then try to connect or flash firmware for your flight controller. These drivers are also attached.