PDF of 191 KB titled only with the number 75003407, an uninformative name that reveals neither brand nor device. The format suggests a manufacturer document number, possibly a component datasheet or application note, though only opening the file will confirm which. For repair purposes such a document is useful only once its subject is matched to the part on the board, so compare printed markings, package type and pin count with the drawings before using any figures or connection details from it.
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 @cyberlanelectonik. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.