BIOS archive for the MacBook Air A1466 on logic board 820-3437-A, the earlier revision letter of that board. Revision A and B can differ, so check the label on the PCB before flashing this 4 MB RAR. Inside should be an EFI image for the SPI chip, used when a machine shows no boot, a chime loop or firmware corruption. Write it with a programmer, but read and save the existing contents first, since the original carries serial number and system identity data you may need to keep.
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.
All sources (5)
The same file was posted more than once. If one link is dead, try the next.
| Channel | Posted | |
|---|---|---|
| @biosarchive | 5 May 2018 | Open file on RM Schematics |
| @pepeelectronica | 24 Apr 2022 | Open file on RM Schematics |
| @generalbios | 8 Oct 2023 | Open file on RM Schematics |
| @schematics_bios | 24 Jul 2026 | Open file on RM Schematics |
| @schematics_bios | 1 Aug 2026 | Open file on RM Schematics |
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 →