PDF document filed under schematics, titled only as unit two in Spanish (unidad 2), which suggests a chapter of a repair or electronics course rather than a board diagram. The name gives no device, brand or board number, so its exact content can only be confirmed by opening it. At 568 KB it is a short text-and-figure document readable in any PDF viewer. Treat it as study or reference material, and check whether it belongs to a numbered series before relying on it for a specific repair procedure.
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.