Repair archive for Apple logic board 820-2390, with the suffix A in the name, which most likely refers to board revision A. The 1.27 MB-class package, 2.15 MB here, does not list its contents, so expect a schematic and possibly a boardview after unpacking. Use the material to trace rails from the charger input to the CPU supplies, find components by designator and work out short-circuit locations. Check the 820 number and revision silkscreened on the board, since later revisions can change parts.
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.
How to open a .zip file
Compressed archive that every operating system opens without extra software.