Apple logic board 820-2532 documentation in a RAR archive of roughly 2.08 MB. The name provides only the board number, so the model, revision and exact files are unknown until extraction. Apple prints these 820-series numbers on its logic boards; verify yours matches. Typical use involves a schematic for tracing power rails and signals and a boardview, viewable in OpenBoardView or FlexBV, for pinpointing components, test pads and the location of a suspected short.
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 @Mac_Shematic_Santale. 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.