A: This usually means a partition table corruption. You need to flash the "GPT" (GUID Partition Table) file. Be careful: Flashing the wrong GPT will hard brick the phone permanently.
If your Vivo V9 is stuck on the logo, your "loader" is broken, and you need a PC-based "Loader tool" to rewrite the firmware. vivo v9 loader
Unlocking the bootloader can pose some risks, including: A: This usually means a partition table corruption
However, thanks to Qualcomm's EDL mode and community-developed flashing loaders (like the Firehose programmer), a dead Vivo V9 is rarely a hardware failure. With the correct drivers, the right firmware (PD1809F), and a reliable PC tool, you can restore the loader, reinstall Funtouch OS, and get another solid year of use from your device. your "loader" is broken