Firmware archive for the MacBook model A1286 with logic board 820-2915, revision A, compressed to 3.89 MB in RAR. A1286 is Apple's model number for the 15-inch MacBook Pro, and the 820 prefix is Apple's logic board numbering. Extract it and confirm the image matches the flash size before writing. Technicians use such dumps to restore a board stuck without chime or boot after a firmware fault. Read the original chip first to keep the serial and machine-specific data, and check the 820 number on the board.
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 @biosarchive. 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.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →