Schematic PDF in a RAR archive for the Apple logic board 820-3330, revision B, project code J31 as given in the name. Apple uses 820-prefixed numbers for its logic boards, with the letter marking the revision, so check both on the PCB before working from the drawings. A technician reads the schematic to follow power sequencing, find the expected rail voltages, identify the parts that generate them and trace signals between the SMC, PCH and connectors. Pairing it with a matching boardview makes locating components much faster.
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 (7)
The same file was posted more than once. If one link is dead, try the next.
| Channel | Posted | |
|---|---|---|
| @schematicslaptop | 2 Jan 2022 | Open file on RM Schematics |
| @pepeelectronica | 24 Apr 2022 | Open file on RM Schematics |
| @boardviewsandachematics | 2 Sept 2025 | Open file on RM Schematics |
| @cyberlanelectonik | 4 Jul 2026 | 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 |
| @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.