Schematics for a device identified only as K520, delivered as a fairly large ZIP archive of 34.8 MB. The name gives no brand or board number, so check the contents to confirm which K520 model it covers before use. Schematic diagrams let a technician trace power rails, follow signal lines between chips and identify components on suspicious nets. The archive size suggests several sheets or files, possibly including boardview data; verify the board revision against the PCB.
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 @esquematicosparatodos. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Built-in OS tools7-Zip