A schematic diagram for Apple hardware (board 820-3243). Shared as “820-3243 iPad PDF SCHEMATIC.pdf” — a .pdf file, 2.04 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 @ShareMan_Electronic_Files. 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.