A schematic diagram for Apple hardware (board 820-00431). Shared as “MAC A1418 (820-00431-A) PDF(PK).pdf” — a .pdf file, 3.93 MB.
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 @pkbiosbdv. 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.
Any PDF readerSumatraPDFFirefox / ChromeFlexBV (links PDF to boardview)