Plug the USB drive into the TV's USB port while the power is off.
Once restarted, you may need to enter the Service Menu (commonly by pressing Input 2580 or Menu 1147 ) to verify the resolution settings or perform a factory reset.
Ensure your USB flash drive is formatted to FAT32 .
Sites such as Zainab Tech and LCD4Hobby provide aggregated lists of firmware files categorized by resolution and tuner type (e.g., R840 or R842). Installation Steps via USB