Working firmware dump for the 15-inch MacBook Pro A1398, model years 2013 to 2014, logic board 820-3787-A. Apple identifies its logic boards with 820-series numbers, and the letter suffix gives the revision. The 5.04 MB ZIP holds an EFI image for writing to the boot ROM chip with an SPI programmer, often to clear a corrupted firmware or a locked board. Read and keep the original chip contents first, since they hold machine-specific data, and check that the image size matches the flash.
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 .zip file
Compressed archive that every operating system opens without extra software.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →