Apple iPhone SE PCB and schematic document, a compact 554 KB PDF. The name suggests it combines circuit drawings with board layout information, though no board number or revision is stated. Such material lets a technician trace rails, match schematic parts to their physical location on the logic board and pick test points for voltage or diode-mode measurements. Open it in any PDF reader, and check which SE generation is on the bench, as boards differ completely between generations.
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_mobiles. 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.