Schematic diagram for the Apple iPhone 7 Plus, described as a 3D version, in a large PDF of about 40 MB. A 3D style document generally shows the logic board with component placement rendered visually alongside circuit details, helping locate parts on the stacked board. Technicians use it to follow power lines, find filters and test points, and diagnose faults such as no power, audio IC or baseband problems. Cross-check against the board markings and a standard boardview before replacing components.
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 @schematic_mobile5. 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.