Archive for the Apple logic board 820-3662, revision A, 1.94 MB in zip form. The Mac model and the exact contents are not stated, so open it to confirm whether it contains a schematic, a boardview or both. Apple's 820 number is silkscreened on the PCB and is the reliable way to match these documents to your board. Use them to trace rails from the charger through to the CPU supplies, locate components and test points, and find a short. Boardview files usually open in OpenBoardView or FlexBV.
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 @notebookschematic. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.