Sequence diagram in PDF form for the Apple 820-01055 logic board. Documents of this kind lay out the power-up order: which rails come up first, which enable and power-good signals trigger the next stage, and what must be present before the system boots. With it a technician can measure rail by rail on a dead board and find the exact step where the chain stops. The revision is not stated in the name, so read it alongside a schematic that matches the number and revision printed on your PCB.
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 @LaptopsBoardview. Enginerys does not host this file.
All sources (4)
The same file was posted more than once. If one link is dead, try the next.
| Channel | Posted | |
|---|---|---|
| @LaptopsBoardview | 1 Jun 2023 | Open file on RM Schematics |
| @generalschematics | 19 Oct 2024 | Open file on RM Schematics |
| @ShareMan_Electronic_Files | 10 May 2025 | Open file on RM Schematics |
| @pkbiosbdv | 27 Oct 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.