Your downloaded file should have a version number higher than your current version. Example:
How to Update Your TCL TV Firmware via USB: A Complete Step-by-Step Guide Tcl Software Update Usb
Roku TVs typically require USB updates only if they have never been connected to the internet. Insert the USB drive into the Roku TV. Press the button on your Roku remote. Select Settings > System > System Update . Choose I can't connect . Your downloaded file should have a version number
The USB drive must be formatted to FAT32. TCL TVs cannot read NTFS or exFAT formats for system updates. Tcl Software Update Usb
Bypasses "System is up to date" messages when a newer version is known to exist.