Duplicate-named RAR archive for Apple board 820-2807, 1.53 MB, matching the size of the other 820-2807 file and likely the same content saved twice. The name states no model or revision, and the inner files are not listed. Compare both archives after extraction if unsure. Apple's 820 numbering identifies the logic board itself; match it to the PCB marking, then use the schematic or boardview to trace rails, locate parts and investigate shorts.
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)