Plug the TV back in. On many models, the update will start automatically; on others, you may need to hold the button on the TV panel until the standby light starts flashing rapidly.
Wait for the process to reach 100%. during this time, as it can permanently damage the motherboard.
You can often find these files hosted on community technical forums or via direct Google Drive links provided by repair specialists. How to Update Smart Tv Software by Usb @KazmiElecom
Compressed .rar (Part 1). Note that you typically need all parts (Part 1, Part 2, etc.) in the same folder to successfully extract the final firmware file. How to Use the USB Boot Firmware
Download all required parts and use a tool like WinRAR or 7-Zip to extract the firmware file (often named allupgrade_506_sos.bin or similar).