This is the specific TV model number (55-inch N770 series).
This confirms the firmware is for a 4K Ultra HD display. Download MS3458 PC757 3840x2160 JVC 55N770 Dump rar
The software has become corrupted and cannot be updated via the standard menu. ⚠️ Important Risks This is the specific TV model number (55-inch N770 series)
Have you already tried a using the physical buttons? Download MS3458 PC757 3840x2160 JVC 55N770 Dump rar