Schematic PDF for Apple project K21, MLB drawing 051-8870 version 3.13.0, compressed in a 3.09 MB RAR. K21 is Apple's internal code name, and the 051 number is the schematic document reference; related files in this set link it to board 820-3023 for the MacBook Air A1369. Use it to trace power rails, check the charging and sequencing logic and identify components around a failure. Confirm the logic board number on the PCB matches before relying on part values.
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.
All sources (8)
The same file was posted more than once. If one link is dead, try the next.
| Channel | Posted | |
|---|---|---|
| @schematicslaptop | 5 Jul 2021 | Open file on RM Schematics |
| @LaptopsBoardview | 17 Aug 2021 | Open file on RM Schematics |
| @pepeelectronica | 26 Apr 2022 | Open file on RM Schematics |
| @generalschematics | 19 Oct 2024 | Open file on RM Schematics |
| @cyberlanelectonik | 18 Jul 2026 | Open file on RM Schematics |
| @schematics_bios | 25 Jul 2026 | Open file on RM Schematics |
| @schematics_bios | 2 Aug 2026 | Open file on RM Schematics |
| @schematics_bios | 14 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.