Package labelled TCL 40D300, a 4.61 MB RAR file. Only the brand and model appear in the name, so the archive may hold firmware, service data or a schematic, and it should be opened and inspected first. If it contains a memory dump, it is intended for reflashing the main board storage chip with an external programmer. Save a copy of the original chip contents before erasing anything, and verify that the main board and panel versions in the set match the unit the dump came from.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @hashmielecom. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.