Updating via USB is a common repair method for these TVs when the software becomes corrupted: : Use a USB drive formatted to FAT32 .
: The native display resolution. Firmware is tailored to the specific panel resolution to ensure the image displays correctly. Updating via USB is a common repair method
: The technical model number of the internal motherboard (PCB). It is critical to match this exactly, as using the wrong firmware can permanently damage ("brick") the TV. Updating via USB is a common repair method
Hold down the on the TV (not the remote) and plug the power cord back in. Updating via USB is a common repair method
Technical YouTube guides like this firmware update tutorial often provide direct links in their descriptions.