Zip archive of about 10.5 MB labelled only for the ASUS X550CC notebook. The name does not say whether it holds a schematic, boardview, BIOS image or a mix, nor does it give a mainboard revision, so unpack it and inspect each file before use. ASUS X-series boards normally carry a main board revision silkscreened near the memory or CPU area, and that marking should match any documents inside. Schematics help follow power rails and signals, while a BIOS dump is written to the SPI flash with a programmer after backing up the original chip.
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 @azvoltagemap. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.