Small 136 byte archive carrying the title Diagnostic and repair technology, a size that cannot hold a meaningful manual, schematic or image, so it is probably a placeholder or incomplete file. No model, manufacturer or board number is given in the name. Proper repair methodology material would explain power-on sequence, measuring rails, finding shorted capacitors and reading signals; obtain a full version and verify its content before depending on it for any board diagnosis.
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 @hrtechno. 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.