Zip archive for Apple logic board 820-3332, revision A, 2.25 MB. The name lists only the board number and revision, with no model name or contents, so look inside before relying on it. Apple identifies logic boards by 820-series numbers printed on the PCB, and matching this number and the revision letter is essential. Schematic and boardview data like this help a technician follow power rails, read the power sequence, find components on both sides and track down shorts. Viewers such as OpenBoardView handle most boardview formats.
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.