: Always check the TCL Support Page or the SmartTech TV Download Center for authorized software.
Give a look here. Anyway i can download the file you were referring to. Software TCL U58S7806S - HDForum Download NT67F02 LF1V498 part5 rar
: Navigate to Settings > Device Preferences > About > System Update and select "Local Update" or "USB Update" if available. : Always check the TCL Support Page or
: While the TV is off, press and hold the physical power button on the TV chassis for about 10 seconds to trigger the update. Download NT67F02 LF1V498 part5 rar
: Technical communities like Elektroda and HDForum are common places where users share specific older versions like LF1V498. How to Install the Firmware