Archive for Apple logic board 820-00840, with the A suffix in the name possibly referring to a board revision. The name does not say which MacBook it belongs to or whether it holds a schematic, boardview or firmware, so check the 4.85 MB contents after extracting. Apple 820 numbers are the key reference for matching repair data. Such files help trace power rails, find test points and diagnose shorts. Confirm the 820 number on the logic board before relying on it.
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 @schematicslaptop. 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.