Power sequence diagram for Apple logic board 820-01055, provided as a 215 KB PDF. The 820 prefix is Apple's own board numbering, visible on the PCB. Technicians follow this chart to see which rail or power-good signal should appear next, narrowing down a dead board to a failed regulator, missing enable or shorted line. Open it in any PDF reader alongside the schematic and boardview, and verify the board number on your unit before measuring against it.
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 @notebookschematic. Enginerys does not host this file.
All sources (2)
The same file was posted more than once. If one link is dead, try the next.
| Channel | Posted | |
|---|---|---|
| @notebookschematic | 20 Jan 2023 | Open file on RM Schematics |
| @schematiclaptopramkushwaha | 13 Sept 2025 | Open file on RM Schematics |
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.