A schematic diagram for Apple hardware (board 820-00239, 820-00923). Shared as “J79_MLB_820-00239-A 820-00923.pdf” — a .pdf file, 3.04 MB.
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 @ShareMan_Electronic_Files. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.
Any PDF readerSumatraPDFFirefox / ChromeFlexBV (links PDF to boardview)