Please follow these steps:

1. Plug a USB-C cable into the SpeedyBee F7 V3 flight controller and connect another end to your computer.

2. Launch the Betaflight configurator on your computer and go to the Blackbox page, then click 'Activate Mass Storage Device Mode'

3. Go to the system's File Explorer and you can find the Blackbox storage chip that could be recognized as a mass storage card. Try to format it to 'FAT' with the allocation unit size as '4096Byte'. Wait for a while until it finishes.

4. Unplug the flight controller from the computer and connect to the computer again to see if the Betaflight can recognize the Blackbox properly.

When the onboard SD card is abnormal (the onboard SD card is displayed in red), as shown in the following figure:

The steps to format the onboard SD card are as follows:

1. Please enter "MSC" in the CLI of the Betaflight ground station.

2， The onboard SD card of F7 V3 will be recognized as a U disk.
Please find the U disk in the computer and format the U disk into FAT32 (default) or FAT (default).
Please choose the appropriate Aocalltion unit size according to your computer, the Aocalltion unit size is 8192 bytes or 4096 bytes.
As shown below:

3. The SD card turns green and the format is successful, as shown below:

What to do if the MSC command still shows errors?

1. Enter CLI and enter:

set sdcard_mode = SPI
save

2. Follow the steps above to activate the mass storage mode and then format the sd card. Then you'll be able to access the onboard flash again.

For flight controllers running iNav firmware.

1."Please enter "msc" in the CLI command to activate "Activate Mass Storage Device Mode"."

2， The onboard SD card of F405 V3 will be recognized as a U disk.
Please find the U disk in the computer and format the U disk into FAT32 (default) or FAT (default).
Please choose the appropriate Aocalltion unit size according to your computer, the Aocalltion unit size is 8192 bytes or 4096 bytes.
As shown below:

3. The SD card turns green and the format is successful, as shown below: