For Apple board 820-2610, this 2.28 MB RAR archive holds repair documents not detailed in the name, which gives no model or revision. Extract it to determine whether a schematic, a boardview or both are included. Apple's own 820-xxxx numbering is printed on the logic board and should match before use. Schematics help trace power rails, enable signals and the boot sequence; boardview files open in OpenBoardView or similar to locate parts, test points and nets around a 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.