A sizeable 15.1 MB zip filed under Apple logic board 820-00850. The name lists no model, revision or contents, but the size suggests more than a single schematic, possibly a boardview, extra documents or firmware. Unpack it and review each file before use. The five-digit 820-00xxx format belongs to newer Apple boards. Match the number printed on the PCB, and if a firmware image is inside, read and save the original SPI chip contents before writing anything.
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 @notebookschematic. Enginerys does not host this file.
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Built-in OS tools7-Zip