Schematic for the Apple logic board 820-3787 revision A, delivered as a 4.01 MB RAR. The name identifies only the board number, not the Mac model, so cross-check it against the 820- number printed on your PCB. Circuit diagrams like this let you follow power rails from the charger IC through to the CPU, identify enable signals and find what feeds a shorted line. Expect a PDF inside that opens in any reader, and pair it with a boardview to locate the parts physically.
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 @schematicslaptop. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.