firmware (specifically the 3840x2160 ENIE version), follow this technical guide. This board is a popular 4K network motherboard used in various TV brands like Onida, JVC, and Microsonic.
Do NOT turn off the power during this process. The TV will typically reboot automatically once finished. Important Notes
Plug the USB drive into the USB 2.0 port of the TV. Force Upgrade: Press and hold the Power button on the TV (not the remote).