Apple logic board schematic for 820-2915 at revision A, an uncompressed PDF of 1.99 MB. It opens directly in any PDF reader, where text search jumps to nets, connectors and reference designators. Check that the board is marked 820-2915 with revision A, as other revisions may differ. Technicians use it to follow the power-on sequence, measure rails at the right points, trace SMC and charging signals, and pinpoint the component responsible for a short or missing voltage.
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 @cyberlanelectonik. 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.