: Technical forums such as Monitor.net.ru often host archive (RAR/ZIP) files for specific mainboards like the 40-OMS82D. USB Preparation

the button once you see a blinking LED or an "Upgrading" message on the screen.

the physical Power button on the TV (usually located on the bottom or back panel). Plug the TV back in while still holding the Power button.

: The most reliable way to get the correct version is to contact TCL Support or their after-sales team with your serial number to receive a secure download link.