Flashing firmware carries a risk of "bricking" your television. If the process is interrupted or the wrong file is used, the TV may not turn on again.
: Place the downloaded firmware file (usually named allupgrade_xxxx.bin or similar) directly into the root directory of the USB drive. Do not put it in a folder. 3. Installation Steps Firmware update for CV-920H-U50 main board? - Facebook
The motherboard's bootloader requires a specific USB format to detect the installation file.
Switch to a different, older USB 2.0 slot if your board has multiple ports.
The USB drive must be formatted entirely to the FAT32 file system.