Spanish-language PDF from a master course in microelectronics, apparently part one of a series, about 904 KB. It is training material rather than a schematic for any specific device; the name names no brand or model. Such course notes typically cover semiconductor fundamentals, component identification, soldering and board-level repair technique. It is useful background for newcomers to circuit repair, but for an actual fault you still need the schematic and boardview for the exact board being worked on.
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 @canalesquematicos. 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.