Apple logic board 820-3462 documentation in a 1.42 MB RAR archive; the name gives no revision, model or file list. Unpack to see whether it contains a schematic PDF, a boardview or both. The 820- prefix is Apple's PCB part number, found printed on the board, and the revision letter should also be confirmed since revisions can differ. Use the material to trace rails, check for shorts to ground and locate components when repairing power or charging faults.
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.
7-ZipWinRARThe Unarchiver (macOS)